Error monitoring is critical to an individual's ability to function autonomously. This study characterized error detection and correction behaviors within the service of everyday tasks in individuals with dementia. Also, the impact of neuropsychological functioning on error detection and correction was examined. Fifty-three participants diagnosed with Alzheimer's disease (AD) or vascular dementia (VaD) were administered a neuropsychological protocol and the Naturalistic Action Test, which requires performance of three everyday tasks. Error detection, correction, and the point at which correction occurred (i.e., microslip—before the error was completed, immediate—just after the error was made, delayed—after performing other task steps) was coded. Dementia participants detected 32.7% of their errors and corrected 75.8% of detected errors. Participants were more likely to engage in microslips than delayed corrections. Tests of executive control and language predicted detection and correction variables; moreover, detection and correction were each related to different aspects of executive functioning. Microslips were related to naming ability. AD and VaD patients did not differ on detection/correction variables, and regression analyses indicated that dementia severity and memory abilities were unrelated to detection/correction. The results specify the error monitoring deficits in AD and VaD and have implications for improving functional abilities in dementia. (JINS, 2008, 14, 199–208.)