Aim: To explore the factors related to the outcome of self-injurious behaviour (SIB) in children with pervasive developmental disorders (PDD). Method: Children with PDD were assessed on individual and environmental variables at time 1 and 3 years later. A questionnaire about the presence or absence of SIB was also administered at both times in order to examine the early course of SIB. Results: Our findings suggest an association between a negative outcome and several aspects of the children's behaviour. Children with a negative outcome differed from the others in having greater speech impairment, more cognitive and adaptive deficits, and more severe signs of autism. When these variables were entered into a multivariate model for predicting the outcome of SIB, only speech deficits (OR[subscript a] 3.5, CI 95% 1.13-13.4) and autism severity (OR[subscript a] 1.1, CI 95% 1.03-1.18) were significant risk factors. Discussion: The importance of these findings for improving our understanding of SIB is discussed.