Male Sprague-Dawley rats were administered a single intraperitoneal injection of N, N-dimethylformamide (DMF, 0.01-1.5 g kg-1) or were exposed for 4 h to DMF vapours (75-900 ppm). The serum activities of the enzymes sorbitol deshydrogenase and glutamate deshydrogenase were used as indicators of liver damage, and were determined at 24, 48 or 72 h post-treatment. Following either route of administration DMF caused concentration-dependent elevations in enzyme activities, the maxima of which occurred later after administration of higher concentrations of DMF than after lower concentrations.