Female genital organs of 340 adult breeding non-pregnant buffaloes were collected from slaughter houses. The uterine lesions were recorded in 45/340 animals and included: endometritis in 29 cases (8.53%), metritis in 5 cases (1.47%), endometrial hyperplasia in 5 cases (1.47%), fibroma in 6 cases (1.76%), serosal cysts in 11 cases (3.24%), adenomyosis in 2 cases (0.58%), perimetrial nodules in 26 cases (7.65%) and uterine adhesions in 3 cases (0.88%). Ultrastructure examination of uterine specimens with inflammatory lesions by transmission electron microscopy revealed presence of degenerated polymorphonuclear cells with many vacuoles in their cytoplasm that sometimes contained electron dense rod-like structures and macrophages in case of acute endometeritis. Fibroblasts, fibrocytes, few mononuclear cells, and collagen fibers in longitudinal and cross sections around the endometrial glands were prominent in case of chronic endometeritis or metritis in addition to presence of degenerated cells with intracytoplasmic electron translucent areas and electron dense debris in lumina of the endometrial glands in acute metritis. The bacterial isolation was positive only in cases of endometritis and metritis in 19/34 animals (55.88%) and included: Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, Citrobacter freundii and Citrobaacter diversus. The frequency of uterine pathological findings in spring and summer (30.33% and 26.66%, respectively) were higher than in winter and autumn (25.00% and 17.24%, respectively) and there was significance (P< 0.05) between incidences of uterine lesions in spring and autumn.