Objective. To assess the agreement of sleep parameters measured by two actigraphs, at two different placements and of self-reported sleep with polysomnography (PSG). Methods. We estimated agreement with PSG for 100 participants at participating centers using Bland-Altman plots. Results. Mean difference to PSG as well as the width of intervals of agreement differed with the placement of the devices. Mean differences to PSG were higher for hip-based measurements compared to wrist placement for most parameters. Conclusions. The agreement of sleep parameters assessed by actigraphy with PSG differs with the placement of the device. The agreement between PSG and self-reported sleep characteristics is comparable to that of actigraphy for some parameters.