The present study was conducted to explore the clinical signs and pathological changes might occur with retained placenta. Sixty-three placenta examined Iraqi buffaloes in Ninevah province during the period from February 2005 to February 2006, were collected after 24 hr postpartum, Result showed variable gross lesions in those examined placenta. Some retained placenta showed severe congestion associated with the presence of focal areas of necrosis and, others suffer from thickening with congested some of the cotyledons. Histologically, the lesions characterized by thickening in wall of maternal blood vessels and, coagulative necrosis appeared in placental plates, maternal caruncles and fetal cotyledon. Infiltration and proliferation of macrophages and binucleated cells, desquamation of syncytiotrophoblast were quite obvious. Moreover, most Retained Placenta sections have revealed dystrophic calcification association with fatty infiltration.