The renal prostaglandins and thromboxanes are powerful autacoids with potential effects on renal hemodynamics, salt and water metabolism, and the immune system. The possibility of adverse effects on renal function in certain patients with renal disease due to cyclooxygenase inhibition with nonsteroidal anti-inflammatory drugs has long been appreciated. Experimental evidence indicates that renal prostaglandin and thromboxane production is increased in several models of renal disease and that similar decrements in renal function occur with cyclooxygenase inhibition and may be due to inhibition of vasodilator prostaglandins. Additionally, several investigators have shown that administration of prostaglandins may be therapeutic in some forms of renal disease, particularly immunologically mediated diseases. Dietary modification to affect prostaglandin production has also been promising in certain experimental models. In contrast to vasodilator prostaglandins, thromboxane is a potent vasoconstrictor and would be expected to have adverse effects on renal function. Despite demonstration of elevated glomerular thromboxane, studies using inhibitors of thromboxane synthesis in immunologically mediated glomerular disease have been disappointing. There is some evidence, however, that these drugs may be of benefit in ureteric obstruction and renal transplant rejection.