Sleeping difficulties are relatively common amongst normal young children at some stage in their development. It is estimated, for example, that approximately 20% of normal 1–2 year olds and 14% of 3 year olds wake regularly during the night (Bernal, 1973; Jenkins, Bax and Hart and Land-sown, 1980). Amongst handicapped children rates of sleeping disturbance tend to be even higher (Richman, Stevenson and Graham, 1975; Richman, Douglas, Hunt, Levere, 1982) and in autistic children, in particular sleeping difficulties are frequently severe and persistent. Thus, De Meyer (1979) found that almost all autistic children had shown sleeping problems at some stage in their development and at an average age of 5½ years, 49% still showed severe sleeping difficulties (as compared with only 3% of normal controls). This additional strain on parents, who already have to cope with many behavioural problems throughout the day, can be considerable, and frequently has a deleterious effect on many aspects of family and marital relationships.