Maltreatment can have a profound adverse effect on the health of individuals with intellectual disabilities (ID). People with ID may also be more likely to experience maltreatment than other groups. Historically, data on prevalence of maltreatment among people with ID have been sparse and methodologically weak but have suggested that the scope of the problem is considerable. Studies published between 1995 and 2005 were reviewed to determine estimated maltreatment prevalence among people with ID based on recent literature. Prevalence estimates for people with ID were compared to estimates for people with no disabilities and people with other types of disabilities. Only five studies provided maltreatment prevalence estimates for people with ID. The limited data suggest that maltreatment is more prevalent for people with ID than for people with no disabilities and may be higher for people with ID than for people with certain other disabilities. Most of the available research is still based on convenience samples. More population-level data are needed to provide reliable estimates of the prevalence of this important health problem. (Contains 4 tables.)