To study the transient diastolic murmur associated with renal failure, we used Doppler echocardiography to characterize flow across the semilunar valves in 10 patients on chronic hemodialysis with a diastolic murmur (group A), 26 patients on chronic hemodialysis without murmurs (group B), and 15 healthy persons (group C). Nine patients in group A had pulmonic valve insufficiency that encompassed 77 +/- 21% (SD) of diastole with peak regurgitant flow velocities of 1.7 +/- 0.3 m/s. Doppler-calculated mean pulmonary artery pressure in 8 of them was 43 +/- 7 mm Hg before dialysis and 20 +/- 12 mm Hg afterward (p less than 0.001). Dialysis reduced the duration of pulmonic insufficiency to 10 +/- 16% of diastole and lowered peak regurgitant flow velocities to 0.2 +/- 0.2 m/s (p less than 0.001 for each). Three patients in group B had aortic valve insufficiency and 3 had pulmonic valve insufficiency like that in group A. Three persons in group C had mild pulmonic valve insufficiency. Thus, transient diastolic murmurs associated with pulmonic valve insufficiency are not uncommon in patients with renal failure; they are related to fluid overload, are diminished by extracellular fluid removal, and reflect correctable pulmonary hypertension.