To fill the knownledge gap on the extension and quality of physical restraints in acute care hospitals a survey aiming at evaluating knowledge, opinions and behaviours of nurses in this area of care was performed. A questionnaire administered to the nurses of a large Italian hospital obtained a response rate of 66.2% (227 nurses) and the situation of 77 patients (15.8% of admitted patients) hospitalised and constrained in the target wards was reported. The physical restraints were widely used in intensive care and medical specialty wards (bed rails and limbs constraints). The main reasons for restraining the patients were: disorientation, agitation, aggressiveness, and balance disturbances. The application of constraints is an autonomous of the nurses decision in 60.8% of cases and the information is seldom reported in clinical or nursing records. Fifty-two per cent of nurses feel uneasy in constraining patients because of the relational implications with relatives. Lack of knowledge on ethical and legal implications and on the possible negative effects of constraining patients, on the different forms of constriction and on alternative strategies warrant an educational intervention to control and improve the implementation of physical measures of containment.