Objective-Sleep problems are common, costly, and potentially fatal in older adults. Sleep problems are also commonly associated with alcoholism. Yet, few studies have examined the combined effects of alcoholism and aging on sleep. The purpose of this study was to investigate the main and interactive effects of diagnostic group and age group on sleep.Method-Male and female alcohol-dependent patients (N=139) and non-alcoholic controls (N=87) completed full-montage polysomnography, structured psychiatric diagnostic interviews, validated rating scales, and alcohol histories at the University of Michigan between 1989 and 1996. The sample was divided for analytic purposes into older (55+ yr) and younger (<55 yr) subgroups.Results-After controlling for gender, race, body mass index, and psychiatric-related sleep symptoms, alcoholics and older adults had significantly decreased total sleep time and increased stage 1 sleep percentage, respiratory distress, and periodic limb movements. Older adults also had decreased delta sleep percentage and shorter rapid eye movement (REM) sleep latencies. Significant interactions were found between alcoholism and age group for stage 1 sleep percentage, sleepdisordered breathing, and periodic limb movements with older alcoholics having the most disturbances. Older alcoholics also had the highest mean values for sleep latency and the lowest mean values for sleep efficiency and delta sleep percentage when compared to the other three groups.Conclusions-Older alcoholics have increased sleep disturbances when compared to younger alcoholics and non-alcoholics of both age groups. Care providers should screen for sleep problems among older adults with alcohol problems.