1. Intravenous ACE inhibitor therapy appears to have a role in the treatment of acute heart failure and early after myocardial infarction. Practical experience with intravenous administration with activation of renin is limited. We report responses to perindoprilat (Pt, 0.67 mg) or placebo (P) infused over 4 h in normotensive male volunteers (n = 12, 19‐28 years, 53‐77 kg) with double‐blind, placebo controlled salt depletion (SD) or salt repletion (SR) as a model of the activated renin system. 2. Salt depletion caused no significant fall in serum sodium (P, 139.4 +/‐ 2.4; Pt, 138.3 +/‐ 1.9) compared with salt replete preparation (P, 139.9 +/‐ 1.2; Pt, 139.7 +/‐ 0.9) but elevation of plasma renin activity 2‐3‐fold. Pretreatment baseline systolic blood pressure following salt depletion (P, 121 +/‐ 9.3/71 +/‐ 7.9; Pt, 121.5 +/‐ 9.6/69 +/‐ 8.1) was higher than following salt replete preparation (P, 114 +/‐ 9.5/61 +/‐ 7.2; Pt, 116.9 +/‐ 6.9/67 +/‐ 7.2). 3. Baseline corrected supine SBP fell significantly and to a similar extent following active treatment regardless of activation of the renin system (SD, ‐14.6 +/‐ 9.5/‐9.4 +/‐ 6.4; SR, ‐12 +/‐ 14/‐10.1 +/‐ 6.6) compared with placebo (SD, ‐6.1 +/‐ 6/‐3.7 +/‐ 5.6; SR, ‐4.7 +/‐ 10/‐1.3 +/‐ 6.5). Heart rate was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)