In order to evaluate captopril effectiveness in the treatment of glomerular albuminuria in nondiabetic patients, an initial study was carried out in 16 patients with proteinuria greater than 1 gr/1, administering captopril, 50 mg/day during a 4 month follow-up period. During that time, urinary albumin levels significantly descended (p < 0.001), with a concomitant rise in serum albumin. We conclude that captopril can be effective as a part of the treatment of albuminuria associated with nephropathy of non diabetic origin.