Comparative morphological and histochemical studies have been made of follicular atresia in the ovaries of goat and sheep. The atretic follicles were classified as preantral (early and late) and antral (Ia, lb, IIa and IIb) follicles. In both preantral and antral atretic follicles, thecal hypertrophy Was MoTe conspicuous in the goat ovary than in sheep ovary. Sudanophillic lipids showed differential distribution in granulosa cell layers. The enzyme 3 beta-HSDH activity increased in antral follicles, becoming intense in the hypertrophied thecae or interstitial gland cells of goat. Our results are compared and contrasted with those on other mammalian species, and possible physiological significance is discussed.