A study was conducted to test the proposal that self-focused attention or monitoring exacerbates the perception of poor daytime functioning in the absence of objective deficits among individuals with insomnia. Fifty-one participants meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for primary insomnia were randomly assigned to a self-focus group (viewing themselves on a TV monitor), a monitoring group (instructed to focus on their thoughts, body sensations, mood, and performance), or a no instruction group while completing a battery of neuropsychological tests. The results indicated that all participants performed within published normative ranges on all tests. The groups did not differ on their objective test performance, but the self-focus group perceived their performance on the tests as significantly worse than the no instruction group. These findings suggest that self-focused attention may contribute to perceived impairment in daytime functioning in primary insomnia.