Objective/Background: Sleep-wake disturbance is associated with poor cognitive functioning and several other adverse outcomes that increase dementia risk in older adults. Targeting sleep-wake disturbance in individuals at risk for dementia may be an important treatment. This study evaluated the efficacy of a four-session multicomponent group intervention for participants with mild cognitive impairment (MCI). Participants: Thirty-five older adults with MCI (mean age = 69.7 years, SD = 9.1), were recruited. MCI was determined via consensus from neuropsychological, medical, and neurological review. Methods: Participants were randomized to the "Sleep Well, Think Well" (SWTW) group condition or a passive control group. The SWTW group received four fortnightly face-to-face sessions conducted by an experienced sleep psychologist and neuropsychologist. The control group received written material detailing strategies to improve sleep quality. Both groups received fortnightly coaching phone calls. The primary outcome was subjective sleep quality, measured by the Pittsburgh Sleep Quality Index (PSQI). Secondary outcomes included actigraphy sleep measures, daytime sleepiness, cognitive functioning, and depression severity. Results: The SWTW intervention was associated with a large and statistically significant improvement in subjective sleep quality (Cohen's d = 0.83, p < 0.02). A moderate nonsignificant effect was evident in reducing daytime sleepiness (Cohen's d = 0.70, p = .08). No significant effects were found on actigraphy markers, depressive symptoms, or tests of cognitive functioning. Conclusions: The eight-week SWTW group intervention for MCI significantly improved subjective sleep quality when compared with a passive control condition. The program also had a moderate (nonsignificant) effect on reducing daytime sleepiness.