Basic and clinical investigations into the roles of arachidonate-derived compounds in regulating renal function under normal and pathophysiological conditions continued to expand over the past year. Exciting new insights regarding the pathobiology of thromboxane A2revealed new roles for this potent cyclooxygenase-derived vasoconstrictor in the glomerular dysfunction that accompanies inflammatory disorders and insulin-dependent diabetes. Major advances have extended our understanding of the proinflammatory actions of leukotriene B4and other 5-lipoxygenase compounds in mediating glomerular injury during experimental glomerulonephritis. Intriguingly, emerging evidence suggests the presence of an anti-inflammatory arm in the lipoxygenase pathway,ie, 15-lipoxygenase, products of which may act as endogenous leukotriene antagonists. New information has also become available about the renal biology of cytochrome P-450 metabolites of arachidonic acid as well as about nonenzymatically generated biologically potent eicosanoids, the F2-isoprostanes.