Urinary PGE 2 and PFG 2α excretion (U PGV) were determined prior, during and after 48 h treatment with angiotensin-II-blocker, Sar 1-Ile 8-angiotensin II (200 μg/kg/3 h), in rabbits maintained on chronic low (LS) or high (HS) salt diets. U PGE2 V and F 2α were significantly (P < 0.001) higher in LS than in HS. Sar 1-Ile- 8-angiotensin II decreased the elevated U PGE2 V and U PGF2α V in LS from 2.60 ± 0.084 μg/24 h to 1.13 ± 0.21 μg/24 h and from 6.63 ± 0.61 to 3.77 ± 0.86 μg/24 h respectively. In animals with HS intake, angiotensin II blockade failed to effect urinary prostaglandin excretion.