This study examines whether there was an association between smoking and nephropathy in patients with non-insulin-dependent diabetes mellitus enrolled in the Appropriate Blood Pressure Control in Diabetes Trial. Sixty-one percent of the patients were smokers; 26% had microalbuminuria, and 14% had overt nephropathy. There was a univariate association between diabetic nephropathy and gender, smoking status, duration of diabetes, hypertension, glycosylated hemoglobin level, creatinine level, body mass index, and cholesterol level. Stepwise logistic regression demonstrated an independent association between smoking and diabetic nephropathy (odds ratio 1. 61; 95% confidence interval 1.01, 2.58). These findings may have important implications for patients with non-insulin-dependent diabetes mellitus who smoke.