Pesq. Vet. Bras. 32(9):824-830, setembro 2012 824 RESUMO.-Objetivou-se realizar um estudo retrospectivo dos principais achados epidemiológicos, clínicos, patoló-gicos e laboratoriais de ovinos acometidos por urolitíase obstrutiva, atendidos na Clínica de Bovinos, Campus Gara- The aim was to conduct a retrospective study of the main epidemiological, clinical, pathological and laboratory ϐindings from sheep suffering from obstructive urolithiasis, in the Agreste region of Pernambuco, Brazil. Thus, 66 medical records of non-castrated male sheep with age from 2 months and 5 years were analyzed. Most cases (79.63%) occurred during the rainy season. Most sheep were raised intensively (87.88%) and all were fed with concentrated ration. Main clinical signs were manifestation of pain, congestion of the mucosae, hyperthermia, and increased abdominal tension associated with urinary tract obstruction. Half of the animals showed total obstruction of the urethra, 69.7% of which died, whilst in cases of partial obstruction only 30.3% died. Laboratorial exams revealed neutrophilia and regenerative left turn, hyperϐibrinogenemia, and azotemia. Urinalysis showed hematuria in 89.29% of the cases, and acidic pH in 46.43%. Erythrocytes, leukocytes, cell desquamation of urethral epithelium, and crystals of amorphous urate predominated in the examination of the sediment. Most frequent gross ϐindings were pyelonephritis (61.54% of cases) and hydronephrosis (50%). In the ureter, ureteritis and hydroureter was observed. The bladder showed diffuse hemorrhagic cystitis (50%) and uroliths (57.69%). In the urethra, uroliths (61.54%) and diffuse hemorrhagic urethritis (57.69%) was found. The uroliths were composed mainly by hydrated calcium oxalate. It is concluded that in the Agreste region of Pernambuco, urolithiasis is an important disease of sheep with high mortality, associated with the ingestion of large amounts of concentrates and mineral supplements.