There is a high prevalence of diabetes mellitus in the population of Saudi Arabia with the majority having non-insulin dependent diabetes mellitus (NIDDM). Random mid-day urine samples were obtained from 100 male [37 insulin dependants DM (IDDM) and 63 NIDDM] and 100 female (51 IDDM and 49 NIDDM) diabetic patients. Eighty-four patients were hypertensive (46 males and 28 females). One hundred and fifty-five subjects, not under medication and without clinical evidence of renal disease, hypertension, or diabetes mellitus were used as controls. Two urinary enzymes, N-acetyl-beta-D-glucosaminidase (NAG) and alanine amino-peptidase (AAP) were measured in the urine, together with total protein and creatinine concentration. Microalbuminuria, glucose and pH were measured using test strips. Increased levels of both NAG and AAP were found in the diabetic subjects. Increased excretion of both these enzymes as well as microalbuminuria was found in the hypertensive groups. The high levels of urinary enzymes found, suggest that renal complications were prevalent in the groups studied. Because of the high incidence of diabetes in Saudi Arabia, a screening program should be established which would include urinary biomarkers for the early detection of renal damage.