Two hundred and five people with intellectual disability, aged 18 years or over, and living in health- or social-services-managed community housing, completed sleep and behaviour questionnaires. An 85.7% return rate was achieved. Settling problems were present in 26.8% and night waking in 55.6% of the subjects. Parasomnias were present in 14% of subjects and 15% of the sample showed some features associated with sleep-related breathing problems. Factors associated with sleep-related problems included gender, aetiology of intellectual disability, epilepsy, treatment with antiepileptic medication, evening caffeine consumption, nocturnal urinary incontinence and ability to communicate. Significant sleep-related problems were demonstrated in this population; some of these problems might be avoided by simple measures.