The prevalence of sleep problems in individuals with intellectual disability (ID) seems to vary between genetic syndromes associated with ID. Different types of sleep disturbances may indicate underlying causes of sleep problems and these types of sleep disturbances may vary between different genetic syndromes. We examined and compared five types of sleep disturbance as well as severity of sleep problems in individuals with Cri du Chat syndrome (CDC), Down's syndrome (DS), Jacobsen syndrome (JS), and individuals with non-specific ID (NS). We used Simonds and Parraga's Sleep Questionnaire (1982) to assess prevalence of types of sleep disturbance and to explore differences in types of sleep disturbance and severity of sleep problems between the four diagnostic groups. In each group, mean scores for Snoring were significantly higher than those for Sleep apnea and Snoring was the most prevalent type of sleep disturbance in CDC, DS, and JS. The mean score on Complaints related to sleep was remarkably high in the JS group. There were no differences in severity of sleep problems between groups. These findings suggest that snoring is an important underlying cause of sleep problems in individuals with CDS, DS, and JS. (Contains 5 tables.)