1 Nadolol excretion was studied in 24 patients with chronic renal failure. 2 The amount of nadolol excreted during the 120-h period after receiving the drug ranged from less than 1% in functionally anephric, patients up to 11.5% in patients with average creatinine clearance of 57.9 +/- 3.6 ml/min/1.73 m2. 3 Renal clearance of nadolol was found to correlate with creatinine clearance; nadolol elimination is retarded in patients with renal failure. 4 Nadolol serum half-life is prolonged in proportion to the remaining renal function. Therefore, dosage intervals in renal patients receiving nadolol should be adjusted to creatinine clearance. 5 Haemodialysis effectively reduced serum concentration of the drug; it may therefore be a useful therapy for drug intoxication.