This study was to search if captopril (C) reduces albuminuria in a group of type II diabetics with diabetic nephropathy (DN). Eleven type II diabetics with DN and hypertension, with albuminuria over 0.30 g/L/24th, fasten blood glucose under 250 mg/dL, serum albumin over 3 g/dL, without infection, cardiac failure or diuretic treatment, were treated with C for six months, as the only treatment for hypertension and albuminuria. Every month, albuminuria in a 24h urinary collection, medium arterial pressure (MAP), serum creatinine and fasten blood glucose were measured. Ten women and one man with 60 (50-70) years of average age (0 to 100th percentile), with 18 (8-35) years of diabetic disease, and 4 (1-7) years of clinic hypertension were studied. Before the treatment with C they had albuminuria of 6.9 (0.7 to 12.5) g/L/24h, MAP of 119.7 (93.2 to 139) mmHg, serum creatinine of 2.2 (0.7 to 7.5) mg/dL and glucose of 168 (78 to 250) mg/dL. After 6 months with C, they had albuminuria of 3.5 (0.2 to 9.6) g/L/24h (p less than 0.01), MAP of 113.4 (92.9 to 132.4) mmHg (p = 0.5), serum creatinine of 2.3 (0.5 to 6.4) mg/dL (p = 0.23) and glucose of 133 (87.5 to 239) mg/dL (p = 0.32). The MAP showed a predictive relation over albuminuria (p = less than 0.004). During the six months of study, C reduced albuminuria in type II diabetics with hypertension and diabetic nephropathy.