We saw three cases of severe reversible azotemia secondary to captopril therapy in hypertension. All patients had extensive peripheral vascular disease involving the renal arteries, and two patients (patients 2 and 3) had high levels of peripheral plasma renin activity. The azotemia occurred approximately two weeks after exposure to captopril, and fever, a maculopapular pruritic cutaneous rash, and eosinophilia developed in two patients (patients 2 and 3). The cause of the azotemia in our patients is not clearly known, since renal biopsies were not performed. The most likely cause for the azotemia was volume contraction with reduction in the glomerular filtration rate, although a direct insult to the kidney could not be excluded.