OBJECTIVE The ability of nicotine to modify withdrawal symptoms in rats chronically treated with alcohol, with respect to locomotor activity and ethanol or nicotine preference, has been evaluated in these studies. RESULTS Preliminary studies showed that locomotor activity increased 8-9 h after withdrawal from chronic nicotine intoxication, which was dose specific; it occurred in rats administered 0.15 mg/kg or 0.6 mg/kg but not the 0.3 mg/kg nicotine dose. Administration of nicotine, either acutely (0.3 mg/kg) during ethanol withdrawal, or chronically (0.15, 0.3 or 0.6 mg/kg) during the chronic alcohol treatment procedure, diminished locomotor activity, which increases significantly, approximately 6-7 h after withdrawal, in rats chronically treated with alcohol. Rats which were chronically treated with alcohol alone or in combination with nicotine, 0.3 mg/kg, showed an increase in ethanol intake when the free choice was performed between ethanol 10% and tap water; on the contrary, when the free choice was performed between ethanol 10% versus nicotine, 0.3 mg/kg, results showed a decrease in ethanol preference and a concomitant increase in nicotine preference. CONCLUSIONS These studies clearly identified the modulatory effects of nicotine, at specific doses, on both motility and preference in rat chronically co-administered nicotine and ethanol.