The impact of elective infrarenal aortic clamping on parameters of renal function was evaluated in 27 extracellular fluid volume expanded patients. Significant transient decreases (p less than 0.05) in glomerular filtration rate were observed in all three groups either in the early or late post-clamp release period, despite maintenance of hemodynamic stability. This study documents transient decreases in glomerular filtration rate which occurred following release of the infrarenal aortic cross-clamp. No clinically important benefit from the use of mannitol and dopamine over extracellular fluid volume expansion with saline alone was demonstrated in the prevention of the changes in renal function associated with aortic cross-clamping.