Rats were given IP injections of ethanol at 0, 400, 800 and 1200 mg/kg. Their activity in running wheels was recorded for one hour post-injection. Ethanol at 800 and 1200 mg/kg depressed running. This effect was greatest during the first 15 min post-injection when activity levels were highest in the nondrugged condition. No evidence of an ethanol-produced increase in running was seen. The monotonic, dose-related activity decrement with no biphasic effect from ethanol in wheel running is similar to some reports of this drug's effect on rats in other paradigms, such as food-motivated operant responding and spontaneous motor activity.