1. Following oral administration of nitromide (3,5-dinitrobenzamide) to rats, 67.9% of the dose was excreted in urine and 32.6% in the faeces in 96 h. Significant biliary excretion of nitromide metabolites also occurred, although no evidence of enterohepatic cycling was obtained. Direct secretion of nitromide metabolites into the gastro-intestinal lumen via the mucosa was detected in surgically modified rats. 2. Six faecal, six urinary and three biliary metabolites, all of which were in a reduced form (as monoamines, diamines and their conjugates) were detected following oral administration. 3. The blood of these animals contained reduced metabolites only, as early as 1 h after oral or intraperitoneal administration of nitromide.