OBJECTIVE To determine whether there are specific situations which may increase the risk of accidental asphyxia during sleep in children with physical and mental disabilities. METHODS Review of all cases where death was attributed to accidental asphyxia caused by unsafe sleeping situations in children listed in the Department of Histopathology database over a 10-year period from March 1989 to February 1999. RESULTS A total of 26 cases were found (M:F, 19:7; age range, 1-48 months; average age, 7.4 months). Of those cases, two involved children with significant mental and physical impairment. Case 1: A 4-year-old boy with Klippel-Trenaunay-Weber syndrome, macrocephaly and severe developmental delay, was found dead with his head hanging over a wooden board attached to the side of his bed. Case 2: A 4-year-old boy with lissencephaly and severe developmental delay was found dead wedged between a retractable mesh cot side and the side of his bed. In both cases the devices resulting in death had been put in place to prevent the boys from falling out of bed. CONCLUSIONS Accidental asphyxia in physically and mentally impaired children may be caused by devices that have been used to prevent injury from falling out of bed. Careful assessment of the specific developmental problems that children suffer should be undertaken before their beds are modified. It may be safer for these children either to have no barrier, or to have drop-sided cots/beds that meet recognized safety standards.