The aim of this report is demonstrating the prevalence of urinary calculi of 55 canines, disposing aspects as mineral composition, urolith localization at the surgery removal, breed and sex and age of the animals attended at Jaboticabal Veterinary Hospital of São Paulo State University, from April 2007 through December 2008. Urinary calculi were obtained from surgery procedure and submitted to qualitative analysis using commercial gear. Pure calculi corresponded to 58.2% of the uroliths and 41.8% mixed uroliths. Among pure uroliths, calcium oxalate corresponded to 46.9%, struvite 34.4%, calcium phosphate 9.4% and ammonium urate 9.4%. Among the mixed ones, 30.4% were struvite and calcium phosphate, 13.0% struvite and calcium carbonate, 13.0% struvite, calcium oxalate and ammonium urate, 8.7% struvite and ammonium urate, 8.7% calcium phosphate and carbonate, 4.3% struvite, calcium phosphate and carbonate, 4.3% struvite, calcium oxalate and carbonate and 4.3% struvite, ammonium urate and cystine. According to localization of uroliths, 67.3% were removed from bladder, 25.5% bladder and urethra, 5.5% urethra and 1.8% renal pelvis. Calculi were obtained from crossbred dogs (21.8%), poodle (16.4%), York Shire (9.1%), Bichon Frise, Dalmatian, Maltese, Rottweiler and Schnauzer (5.5% each ones), English Cocker Spaniel, Pinscher and Teckel, (3.6% each ones), American Cocker Spaniel, American Pit Bull, Basset Hound, Bull Terrier, Collie, Pekingese, Pug and Shi Tzu (1.8% each ones). Besides, 76.4% of the uroliths were obtained from males and 23.6% from females. Mean age of animals was 7 ± 3.3 years. Concluding, pure uroliths were more prevalent and calcium oxalate the most found among all of the calculi analyzed; the main localization of the obtained uroliths were the bladder, the main breed of animals submitted to surgical removal was crossbred dog, male dogs and adults were more prevalent. Yet, it is suggested the importance of the removed urolith analysis, essential to the clinical treatment and prevention of further calculi formation.