1-bromopropane (1-BP) has been used in numerous purposes such as an intermediate in the synthesis of pharmaceuticals, a solvent for fats, waxes, or resins and a substitute for chlorofluorocarbons that destroy the ozone layer. However, the studies related to the modulation of activities of hepatic cytochrome P450s (CYPs) are not reported yet. This study was the first study to investigate the potential effect for the activities of hepatic CYPs by the treatment of 1-BP in vivo. When 1-BP was treated to male ICR mice by dose-dependently at the dose levels of 200, 500 and 1,000 mg/kg of body weight once, the activity of CYP2E1 was selectively increased for 24 h. The inductive potency for the activity of CYP2E1 by 1-BP was equal to induction by acetone a well-known selective CYP2E1 inducer. The present results indicated that 1-BP would affect the metabolism of 1-BP itself and/or other xenobiotics.