Two to four weeks after the left renal artery was clipped and the contralateral kidney was left untouched in Sprague-Dawley rats (the two-kidney Goldblatt preparation), the clips were removed under ether anesthesia. The next day the rats were anesthetized (sodium pentobarbital) and renal functions of both kidneys were measured before and after an i.v. infusion of 2-chloroadenosine (3.6 nMol/min). Then renal cortical renin was measured by incubating tissue homogenate with rat renin substrate and using radioimmunoassay to determine the rate of angiotensin I production. Renal cortical renin was elevated above control in the previously clipped left kidneys and suppressed below control in the right kidneys; on the average, there was a 30-fold difference in renins of the two kidneys. Despite this difference, the 2-chloroadenosine infusion induced similar hemodynamic changes (clearances of inulin and p-aminohippurate, filtration fraction) in the two kidneys. These results are inconsistent with the hypothesis that renal renin is an important determinant of adenosine-induced renal hemodynamic changes.