Literary sources provide considerable information on the existence of various malignant tumours in the classical period. Based on a close reading of the ancient Greek medical treatises, this paper traces the history of the treatment of cancer by examining the theories of tumour formation, as they were codified by leading physicians of antiquity, together with the therapeutic methods they proposed in their writings. The discussion focuses on a series of medical texts beginning with the Hippocratic corpus (ca. 460–370 B.C.) and the voluminous works of Galen (129–199 A.D.) and extends to medical handbooks (Oreibasios, Aetios of Amida, Paul of Aegina) composed in subsequent centuries up to the end of the ancient world (VII c. A.D.).