It has been shown that the glomerular filtration rate increases after a meat meal. We examined in humans whether enalapril, which has been shown to decrease glomerular capillary pressure in rats with chronic renal failure, could attenuate the renal response to a meat meal. Twelve healthy volunteers were studied after an oral protein load, 1.5 g/kg body weight, as lean cooked beef meat, and on a separate day, after eating the same meal with prior oral intake of enalapril. On the control day, creatinine clearance increased from 114.3 ± 4.7 before the meal to 137.1 ± 4.7 ml/min/1.73 m2 after the meal (p < 0.001). On the enalapril intake day, creatinine clearance increased from 113.7 ± 5.6 before the meal to 128.3 ± 5.8 ml/min/1.73 m2 after the meal (p < 0.01). However, the mean increase in creatinine clearance was lower on the enalapril intake than on the control day (14.0 ± 4.3 vs. 21.0 ± 4.1%, p < 0.05). Mean arterial pressure before the meal was lower on the enalapril intake day than on the control day (76.2 ± 3.5 vs. 84.2 ± 3.6, p < 0.01). Likewise, postprandial mean arterial pressure was lower on the enalapril day compared with the control day (69.9 ± 2.8 vs. 78.5 ± 3.7, p < 0.01). We conclude that enalapril blunts the hyperfiltration which follows a meat meal.