People with intellectual disabilities appear to be more vulnerable to victimization. However, few studies have assessed victimization in these groups and those that do exist are highly heterogeneous and tend to focus only on specific forms of violence. This study attempts to shed light on the phenomenon of victimization among adults with intellectual disabilities by assessing victimization and poly-victimization throughout their life course. The sample consisted of 260 adults (154 men and 106 women) with an intellectual disability diagnosis, recruited from the Catalan Federation for People with Intellectual Disabilities (DINCAT) in Spain. They ranged in age from 20 to 71 years (M = 41.69, SD = 12.05). Victimization experiences were assessed by means of an adaptation of the retrospective version of the Juvenile Victimization Questionnaire (JVQ). The results showed that 96.9% of the participants had suffered some kind of victimization throughout their lives. With respect to the types of victimization, the most frequent were common victimization (87.7%), witnessing and indirect victimization (67.3%), victimization by caregivers (59.2%), sexual victimization (35%), and electronic victimization (23.5%). Women and early adults tended to experience higher rates of victimization. The poly-victimized group experienced 13 or more incidents of victimization throughout their lives. This study highlights the elevated rates of lifetime victimization among people with intellectual disabilities. It adds to previous evidence that special protection programs are required to address this issue and emphasizes the need for prevention and intervention measures in this particularly vulnerable group.