The ability to monitor the source of remembered information and related reflective cognitive processes was examined in normal volunteers and detoxified alcoholics. Normal volunteers were very accurate judges of whether remembered events were presented as stimuli or were self-generated, even when memory was tested 2 days later. In contrast, a subgroup of otherwise cognitively unimpaired alcoholics demonstrated impairments in the ability to track the source of remembered knowledge and were also less able to inhibit intrusion errors in recalling information from memory. These findings provide preliminary evidence of an impairment in cognitive control functions in certain alcoholics. This conclusion is supported by associated findings indicating that, among alcoholics, performance on explicit memory tasks that required reflective cognitive operations were positively correlated with glucose utilization rates in left prefrontal, temporal, and posterior orbital frontal cortical regions.