Physical restraints have been subject of extensive public debate during recent years. Reliable epidemiological data demonstrate that these devices are used as routine measures in nursing homes. However, less is known about the frequency of physical restraint use in hospitals. This overview aims to identify and critically appraise prevalence and incidence studies on physical restraints in hospitals. A systematic literature search covering CINAHL, Embase, and Medline revealed 72 references. Eight studies met the inclusion criteria. Only 4 studies present a precise definition of physical restraint measures, and these definitions vary. Bedrails are included in only 2 studies. Data collection methods cover interviews with nurses, analysis of patients' records, and direct observations. Only 4 studies mention the rationale for the chosen sample size. Two out of 8 studies mention valid steps to avoid bias. Overall, the methodological quality of the studies was limited. Only one small study presents data from German hospitals. Future epidemiological studies should adapt internationally consented quality criteria.