The current research considered parent report of sleep problems in children with an intellectual disability (ID). Of specific interest were parents who reported child sleep issues/disturbances but who did not consider their child to have a sleep problem. Also of interest was the use of a general parent-training program to treat both the sleep and behaviour problems in children with an ID. Study 1 examined parent perceptions regarding sleep in children with an ID. Parents who reported a child sleep problem provided information on the types of sleep treatment tried and rated their effectiveness. Overall, 243 questionnaires were completed by parents of children with a range of disabilities aged between 3.1 to 18.7 years. While 62% of parents rated their child as displaying problematic night settling, night waking, early waking, or other disturbing sleep behaviours, only 27% of parents considered their child to have a sleep problem. A higher number of parents (75%) than expected had tried at least one type of intervention, although it was not possible to discern 'self help' treatments from 'professionally sought' treatments. Study 2 investigated child and parent factors associated with parent perception of sleep problems in children with an ID. Seventy-six parents from Study 1 completed measures in relation to child adaptive and daytime behaviour, parent stress, locus of control, personality (extraversion, neuroticism, and psychoticism), parenting competence, and perceived control over the child's sleep and daytime behaviour. Based on parent report on a sleep measure and response to the question 'do you think your child has a sleep problem' parents were allocated into one of three sleep groups: Parents who recognised a sleep problem (RSP, N=20), parents whose child did not have a sleep problem (NSP, N=35), and parents who did not recognise their child to have a sleep problem (USP, N=21). The results revealed differences between parents who do (RSP) and parents who do not (USP) recognise their child's sleep problem. These differences related to amount of child sleep (as reported by parents) and parent perceived control over the child's sleep and daytime behaviour. Study 3 examined the efficacy of a general parent-training (behaviour management) program, with sleep used as the training exemplar, for the treatment of sleep problems in children with an ID. Of the 20 parents in the RSP group in Study 2, five agreed to take part in Study 3 and three completed the intervention. The effect of the intervention on (a) a targeted sleep problem, (b) a targeted behaviour problem, (c) other sleep and daytime behaviours, (d) parent stress, (e) parent sleep, (f) parent sense of competence, and (g) parent perceived control over the child's sleep and daytime behaviour were examined. All parents reported an improvement in target sleep behaviour, and at follow-up all of the parents no longer considered their child to have a sleep problem. One parent reported a decrease in stress and an increase in measures of perceived control, and parenting competence, while two parents showed minimal to no improvement on child and parent outcomes.