1. Accumulation and possible induction in the metabolism of triethoxybenzoylpropionate were studied in rats in relation to the choleretic effect of the drug. Daily oral administration of [14 C] triethoxybenzoylpropionate showed no accumulation of drug or metabolites. Pre-treatment of rats with the drug did not induce its own metabolism or the metabolism of aminopyrine, p-nitroanisole, hexobarbital or zoxazolamine. 2. Choleresis in rats induced by triethoxybenzoylpropionate resulted from enhanced formation of the bile acid-independent fraction of canalicular origin, presumably mediated by the increased transfer of sodium into the canaliculi. This was not altered by repeated pre-treatment with the drug, in accordance with the metabolic findings.