Ill health forced Heidenstam to spend most of his youth in the central and eastern Mediterranean countries. His first book of poems, Vallfart och vandringsår (1888; “Pilgrimage and Wander Years”), full of the fables of the southern lands and the philosophy of the East, was an immediate success with the Swedish public. With his essay “Renässans” (1889) he first voiced his opposition to naturalism and the realistic literary program in Sweden.

His efforts toward the realization of a new Swedish literature include two volumes of poems, Dikter (1895) and his last volume, Nya dikter (1915), many poems of which are translated in Sweden's Laureate: Selected Poems of Verner von Heidenstam (1919). He also wrote several volumes of historical fiction, the most important of which are Karolinerna, 2 vol. (1897–98; The Charles Men), and Folkungaträdet (1905–07; The Tree of the Folkungs). After the turn of the century Heidenstam's works lost their popular appeal, and he wrote virtually nothing during the last 25 years of his life.