Experimental alterations in renal haemodynamics have been observed in obstructive jaundice and these may be the pathophysiological mechanism of increased renal susceptibility to injury in obstructive jaundice. Dynamic 99mTc-DTPA renal scintigraphy was done before and eight weeks after elective hepatobiliary surgery in six patients with obstructive jaundice (bilirubin greater than 100 mumol/l) and in six non-jaundiced control patients to assess changes in glomerular filtration and renal blood flow. Glomerular filtration was lower preoperatively in the jaundiced patients than in the control patients. Glomerular filtration increased postoperatively in jaundiced patients, but decreased in control patients. Renal blood flow was reduced postoperatively in control patients, but not in jaundiced patients. The changes in renal blood flow were different for each group of patients. These results provide clinical evidence of altered renal haemodynamics and a reversible impairment of glomerular filtration in obstructive jaundice. The changes seen in renal blood flow may be the underlying mechanism of increased renal susceptibility to injury.