BACKGROUND Physical restraints are used in critical care units in an attempt to reduce the risk of treatment interference. Their use remains controversial and there are concerns regarding the effectiveness and safety of restraint techniques. There are few data available on the prevalence of physical restraint use in Paediatric Intensive Care Units (PICU) in the UK and we have therefore conducted a cross-sectional survey to define current clinical practice. METHODS A postal questionnaire was sent to all UK PICU with questions on the use of physical restraint techniques, including the use of splints across the joints of limbs and of securing limbs to the bed. Consent issues were also addressed. RESULTS Of those units responding 68% reported that physical restraint techniques were used within those units. Ten units (36% of those responding) reported the use of manual holding of patients, 16 units (57% of those responding) reported the use of splints across the joints of limbs, three units reported the use of swaddling as a restraint technique while one unit secured limbs of patients to the bed. None of the units obtained written consent prior to the use of physical restraints and 53% obtained verbal consent. CONCLUSIONS Physical restraint is a commonly used technique on PICU in the UK. There is considerable variation in clinical practice and current clinical guidelines which are available do not deal specifically with children. Prospective randomized trials would be necessary to fully investigate the role of physical restraints amongst critically ill children.