Serum angiotensin-converting enzyme (SACE) was significantly elevated in 16 of 48 patients with various types of chronic renal disease not on hemodialysis [45.6 ± (SD)16.7 nmol/min/ml, p < 0.001] and in 17 of 52 patients with chronic renal disease on maintenance hemodialysis (43.2 ± 13.8, p < 0.001) in comparison with 58 healthy adult controls (32.2 ± 9.8). There was no significant relationship between SACE and renal function as indicated by serum creatinine and creatinine clearance, or the presence or absence of maintenance hemodialysis, except for a transiently increased elevation of SACE immediately post-dialysis due to hemoconcentration. There was a statistically insignificant positive correlation between SACE and 24-hour urinary protein excretion (r = 0.254, n = 21). Mean blood pressure measured in patients on maintenance hemodialysis was inversely related to SACE (p < 0.05) following dialysis. Chronic renal disease irrespective of severity and therapy tends to be associated with elevated SACE and must be considered in the evaluation of sarcoidos