This study proposes a method to assess voluntary alcohol drinking in socially living squirrel monkeys. Group-housed squirrel monkeys were induced to drink a sucrose solution and subsequently an etbanol/sucrose solution in an experimental chamber attached to the home colony room, allowing the daily intake to be monitored for each individual without disrupting the social context. Sucrose concentration (0.03–0.6 M, corresponding to 1–20%) and ethanol concentration (0–4%) were gradually increased in tap water and in a 0.6 M (ca. 20%) sucrose solution during daily 30-min and 10-min sessions, respectively. Blood ethanol levels ranged from 10–50 mg/dl and remained below intoxication level. These experiments demonstrate that it is feasible to arrange conditions under which individual socially housed squirrel monkeys voluntarily drink a sweetened ethanol solution. Behav Pharmacol 1998; 9:363–367 1998 Lippincott-Raven Publishers.