Pain coping is thought to be the most significant behavioural contribution to the adjustment to pain. Little is known about how those with intellectual and developmental disabilities (IDD) cope with pain. We describe parental reported coping styles and how coping relates to individual factors. Seventy-seven caregivers of children and adults with IDD reported on coping styles using the Pediatric Pain Coping Inventory (PPCI), pain behaviour using the Non-Communicating Children's Pain Checklist-Revised (NCCPC-R), illness-related interactions using the Illness Behaviour Encouragement Scale (IBES) and past pain experience using the Structured Pain Questionnaire. Scores were compared across mental ages and interactions between pain coping and the other factors were explored. A Multivariate Analysis of Variance (MANOVA) by mental age group ("[less than or equal] 4 years", "5-11 years" and "[greater than or equal] 12 years") revealed that those in the "5-11 years" mental age group used more coping styles than those in the "[less than or equal] 4 years" mental age group, and those in the "[greater than or equal] 12 years" group used more cognitively demanding coping styles than the other two groups (F[subscript (10,130)] = 2.68, p = 0.005). Seeking Social Support (r = 0.39, p = 0.001) and Catastrophizing/Helplessness (r = 0.33, p less than 0.01) coping styles were significantly related to a greater display of pain behaviour. Those with younger mental ages, who Seek Social Support or Catastrophize, also displayed more pain behaviour, which may be an attempt to seek external resources when pain is beyond their ability to deal with independently. (Contains 2 tables.)