Male rats were intubated with either 3, 2, or 0 g/kg alcohol, twice daily, for 7 months and were then bred to untreated females. At 18 and 58-62 days of age, male offspring were tested for passive avoidance learning. At 82-88 days of age, another group of male offspring were tested for open field activity after receiving 0, 0.1, or 0.4 mg/kg physostigmine, a cholinesterase inhibitor. Offspring sired by alcohol-treated fathers required more trials to reach criterion in the passive avoidance task at 18 days of age, but did not differ significantly at 58-62 days of age. These offspring were more active in the open field compared with controls after receiving vehicle, but did not differ from controls after receiving physostigmine. These results suggest animals sired by alcohol-treated fathers are more active than controls, and this effect is cholinergically mediated. These results are of interest because of their possible relevance to the hyperactivity noted in children born to alcoholic fathers.