The effects of halothane on renal function and consumption of oxygen (&OV0312;o2) have been studied in dogs, with and without diuresis. With diuresis induced by a variety of intravenous solutions and infusion rates, urinary flow rates during halothane anesthesia were relatively low and urine had an osmolality approximately twice that of plasma. Increasing halothane had little effect on this or other aspects of renal function, including glomerular filtration rate, renal blood flow, and the relation between tubular reabsorption of sodium and nonbasal renal &OV0312;o2. Approximately 28 equivalents of sodium were reabsorbed per mole of nonbasal oxygen consumed, which is the value observed by others in a variety of other situations. Conditions of the nondiuresis situation were similar to those under which whole-body, myocardial, cerebral, and skeletal muscle &OV0312;o2previously were demonstrated to be decreased with increased halothane. Renal &OV0312;o2in this situation was 7 to 8 per cent of whole-body &OV0312;o2and was little changed by increasing halothane from 0.1 to 1.5 per cent.