Italian pathologist who, as professor of general pathology at the University of Turin, made it one of the most important European centres of medical scholarship. Among those who studied or worked in his laboratory were Edoardo Bassini, the surgeon who perfected the operation for inguinal hernia (Bassini's operation); Carlo Forlanini, who introduced therapeutic pneumothorax in treating pulmonary tuberculosis; and Antonio Carle and Giorgio Rattone, who demonstrated the transmissibility of tetanus.

Bizzozero investigated the formation of blood cells and described and named platelets, the small particles important in clotting. He is often recognized as having rediscovered Helicobacter pylori, a bacteria that causes chronic gastritic disease. Bizzozero also contributed to knowledge of histology and public health, emphasizing the control of malaria and tuberculosis.