It is known that while Hippocrates was alive, he was admired as a physician and teacher. His younger contemporary Plato referred to him twice. In the Protagoras Plato called Hippocrates “the Asclepiad of Cos” who taught students for fees, and he implied that Hippocrates was as well known as a physician as Polyclitus and Phidias were as sculptors. It is now widely accepted that an “Asclepiad” was not a temple priest or a member of a physicians' guild but instead was a physician belonging to a family that had produced well-known physicians for generations. Plato's second reference occurs in the Phaedrus, in which Hippocrates is referred to as a famous Asclepiad who had a philosophical approach to medicine.

Meno, a pupil of Aristotle, specifically stated in his history of medicine the views of Hippocrates on the causation of diseases (human disease), namely, that undigested residues were produced by unsuitable diet and that these residues excreted vapours, which passed into the body generally and produced diseases. Aristotle said that Hippocrates was called “the Great Physician” but that he was small in stature (Politics).

These are the only extant contemporary, or near-contemporary, references to Hippocrates. Five hundred years later, the Greek physician Soranus (Soranus Of Ephesus) wrote a life of Hippocrates, but the contents of this and later lives were largely traditional or imaginative. Throughout his life Hippocrates appears to have traveled widely in Greece and Asia Minor practicing his art and teaching his pupils, and he presumably taught at the medical school at Cos quite frequently. His birth and death dates are traditional but may well be approximately accurate. Undoubtedly, Hippocrates was a historical figure, a great physician who exercised a permanent influence on the development of medicine and on the ideals and ethics of the physician.

Hippocrates' reputation, and myths about his life and his family, began to grow in the Hellenistic period (Hellenistic Age), about a century after his death. During this period, the Museum of Alexandria (Alexandrian Museum) in Egypt collected for its library literary material from preceding periods in celebration of the past greatness of Greece. So far as it can be inferred, the medical works that remained from the Classical period (among the earliest prose writings in Greek) were assembled as a group and called the works of Hippocrates (Corpus Hippocraticum). Linguists and physicians subsequently wrote commentaries on them, and, as a result, all the virtues of the Classical medical works were eventually attributed to Hippocrates and his personality constructed from them.

The virtues of the Hippocratic writings are many, and, although they are of varying lengths and literary quality, they are all simple and direct, earnest in their desire to help, and lacking in technical jargon and elaborate argument. The works show such different views and styles that they cannot be by one person, and some were clearly written in later periods. Yet all the works of the Corpus share basic assumptions about how the body works and what disease is, providing a sense of the substance and appeal of ancient Greek medicine as practiced by Hippocrates and other physicians of his era. Prominent among these attractive works are the Epidemics, which give annual records of weather and associated diseases, along with individual case histories and records of treatment, collected from cities in northern Greece. Diagnosis and prognosis are frequent subjects. Other treatises explain how to set fractures (fracture) and treat wounds (wound), feed and comfort patients, and take care of the body to avoid illness. Treatises called Diseases deal with serious illnesses, proceeding from the head to the feet, giving symptoms, prognoses, and treatments. There are works on diseases of women, childbirth, and pediatrics. Prescribed medications, other than foods and local salves, are generally purgatives to rid the body of the noxious substances thought to cause disease. Some works argue that medicine is indeed a science, with firm principles and methods, although explicit medical theory is very rare. The medicine depends on a mythology of how the body works and how its inner organs (organ) are connected. The myth is laboriously constructed from experience, but it must be remembered that there was neither systematic research nor dissection of human beings in Hippocrates' time. Hence, while much of the writing seems wise and correct, there are large areas where much is unknown.

The Embassy, a fictional work that connects Hippocrates' family with critical events in the history of Cos and Greece, was included in the original collection of Hippocratic works in the Library of Alexandria (Alexandria, Library of). Over the next four centuries, The Embassy inspired other imaginative writings, including letters between Hippocrates and the Persian king and also the philosopher Democritus. Though obviously fiction, these works enhanced Hippocrates' reputation, providing the basis for later biographies and the traditional picture of Hippocrates as the father of medicine. Still other works were added to the Hippocratic Corpus between its first collection and its first scholarly edition around the beginning of the 2nd century AD. Among them were the Hippocratic oath and other ethical writings that prescribe principles of behaviour for the physician.

Technical medical science developed in the Hellenistic period (Hellenistic Age) and after. surgery, pharmacy, and anatomy advanced; physiology became the subject of serious speculation; and philosophic criticism improved the logic of medical theories. Competing schools in medicine (first Empiricism and later Rationalism) claimed Hippocrates as the origin and inspiration of their doctrines. In the 2nd century AD, the physician Galen Of Pergamum developed his magnificent medical system, a synthesis of preceding work and his own additions that became the basis of European and Arabic medicine into the Renaissance. Galen was argumentative and long-winded, often abusive of contemporaries and earlier physicians, but at the same time, with exaggerated reverence that ignored five centuries of progress, he claimed that Hippocrates was the source of all that he himself knew and practiced. For later physicians, Hippocrates stood as the inspirational source, while the more difficult Galen offered the substantial details.

As time went on, reverence for the past had to contend with new notions of scientific method and new discoveries. In the process, Galen's authority was undone, but Hippocrates' eminence as father of medicine remained. Scientific progress in fields such as anatomy, chemistry, microbiology, and microscopy, especially beginning in the 16th and 17th centuries, demanded that Galen's medicine be criticized and revised part by part. Arguments against Galenic medicine were often more effective when they were presented as returns to true Hippocratic medicine. New scientific methodology argued for a return to observation and study of nature, abandoning bookish authority. The simple and direct writings of the Hippocratic Collection read well as sample empirical texts that eschewed dogma. By the late 19th century, Galen was irrelevant to medical practice, and general knowledge of Hippocratic medical writings was beginning to fade. However, today Hippocrates still continues to represent the humane, ethical aspects of the medical profession.

A number of idealized images of Hippocrates have survived from antiquity, but none that seems to derive from a contemporary portrait.