Sixty-six dogs diagnosed with cystolithiasis at animal clinics in the Busan area between April 2002, and April 2003, were reviewed. The chemical analysis of cystoliths from 66 dogs indicated that the predominant mineral component was struvite (45 dogs), calcium oxalate (14 dogs), or urate (6 dogs). Animals affected with struvite were grouped into four (s-1; struvite only, s-2; struvite mixed with lesser quantities of calcium oxalate or ammonium urate, s-3; nuclei and lamination, s-4; struvite nucleus surrounded by other minerals), with calcium oxalate into six(o-1; calcium oxalate monohydrate only, o-2; calcium oxalate dihydrate only, o-3; combination of calcium oxalate monohydrate and dihydrate, o-4; calcium oxalate nucleus surrounded by other minerals, o-5; 100% calcium oxalate monohydrate nucleus surrounded by 100% calcium oxalate dihydrate, o-6; mixed calcium oxalate monohydrate nucleus surrounded by mixed calcium oxalate dihydrate), and with urate into two(u-1; ammonium acid urate only, u-2; ammonium acid urate mixed with lesser quantities of other minerals). In this study, the numbers of 4 groups of struvite were (s-1; 10, s-2; 9, s-3; 21, s-4; 5), 6 groups of calcium oxalate were (o-1; 0, o-2; 1, o-3; 2, o-4; 3, o-5; 2, o-6; 6), and 2 groups of urate were (u-1; 6, u-2; 0). The data from each group was analyzed and compared. Shih Tzu(14 cases), Yorkshire terrier(10 cases), mixed-breed(10 cases) and Miniature schnauzer(7 cases) were more frequently affected than the other breeds. Females(40 cases) were affected more than males(26 cases). Twenty-nine dogs had cystoliths associated with a bacterial urinary tract infection, and uroliths tended to recur. We conclude eradication of urinary infection along with appropriate food (e.g. prescription diet) with client compliance should help in reducing the incidence or severity of the disease.