Polysomnography (PSG), the gold standard sleep-assessment methodology, is impractical for many applications. Although alternative assessment methodologies are available, it is not clear which most correlates with PSG measures. This study compared sleep log (SL), actigraphy (ACT), and the REMview (RV) device for estimating PSG sleep measures. Thirty-three participants with various sleep-disorder diagnoses underwent 1 night of monitoring with PSG, RV, ACT, and SL. RV provided accurate estimates of most sleep variables. The accuracy of ACT and SL estimates depended on the sleep variable. These findings indicate that the selection of an alternative methodology should consider the sleep measure of interest in addition to the relative merits and drawbacks of each device.