The effect of dopamine on liver function and on renal blood flow and the glomerular filtration rate was studied in 13 patients suffering from liver cirrhosis. Hence, the BSP retention and 131I BSP clearance was determined and also the clearance of 99mTc DTPA and of 125I hippuran in decreasing concentrations, as well as under steady state conditions. Methodological problems arising from the application of the slope clearance technique in cirrhotic patients are discussed. Dopamine did not affect the BSP clearance and BSP retention, but a significant increase in renal plasma flow was observed. The glomerular filtration rate was not significant altered.