Urinary enzyme activities of alanine aminopeptidase, gamma-glutamyl transpeptidase, alkaline phosphatase, N-acetyl-beta-D-glucosaminidase and beta-glucuronidase were determined in 15 dogs with leishmaniasis and in a group of eight normal dogs. Serum creatinine and blood urea nitrogen concentrations were also measured and renal histology was examined. All the affected dogs had renal lesions. However, no significant differences in blood urea nitrogen and creatinine concentrations were found between the control group and the affected group. The urinary enzyme activities of gamma-glutamyl transpeptidase (P < 0.01), N-acetyl-beta-D-glucosaminidase (P < 0.01) and beta-glucuronidase (P < 0.05) were significantly higher in the affected dogs. Urinary enzymes therefore seem to be a more sensitive and reliable test for assessing early renal damage in canine leishmaniasis than serum creatinine or blood urea nitrogen concentrations.