SUMMARY In a retrospective study of neoplasms in Equidae presented to the Animal Disease Diagnostic Laboratory, Purdue University, from Jan 1, 1970, to Dec 31, 1974, data were compiled on numbers and anatomic sites of neoplasms as well as on age, sex, and breed of subjects from which the neoplasms were taken. During this 5-year period, 21 neoplasms were diagnosed from 687 equine necropsies (3.1%) and 215 from 635 biopsies (33.9%), totaling 236 neoplasms from 1,322 cases (17.9%). The most common neoplasms were sarcoids (43.6%) and squamous cell carcinomas (24.6%). Papillomas (5.5%), nerve sheath tumors (4.2%), melanomas (3.8%), lipomas (3.0%), granulosa cell tumors (2.5%), fibromas (2.1%), cholesteatomas (1.3%), and lymphosarcomas (1.3%) were less common.