BACKGROUNDS: Uterine infection is a amajor problem in reproductive management. OBJECTIVES: The aim of this study was to find out the common pathological condition of cattle and buffaloes' uteri in the Ahwaz region and, also to compare uterilesions. METHODS: One hundred and thirty eight cattle and 101 buffalo uteri were examined for macroscopic lesions, opening them through the cervix to the apex of the animals' horns. The prepared tissue sections were stained with hematoxylin, eosin, and Giemsa staining. Standard bacteriorogical works, were used for the isolation and identification of aerobes and anaerobes. RESULTS: Depending on the severity of the lesions, endometritis was scored from mild (level 1) to severe (level 4). Level 1 including 39 cows (19.69%) and 36 buffaloes (28.8%); Level 2 including 37 cows (18.68%) and 28 buffaloes (22.4%); Level 3 including 23 cows (11.61%) and 22 buffaloes(17.6%); and, Level 4 including 17 cows (8.58%) and 5 buffaloes (4%). Other lesions consisted of acute metritis: (cows=4.54%), buffalo=0.8%); chronic metritis (cows= 2.02%) and buffaloes=2.4%; granulomatous metritis cow (0.5%) and buffalo (0.8%); perimetritis (cows (3.3%) and buffaloes (1.6%); pyometra: (cow 0.5%) and buffalo (0.8%); external cysts: (buffalo 0.8%); and, haemangioma: (cow (0.5%) and buffalo (0.8%). No significant correlation was found among the lesions, except for acute metritis, (p=0.475). CONCLUTIONS: Conducting a clinical and paraclinical study on fertile animals in the Ahwaz region is highly recommended to reduce the economic losses due to uterine infection.