Introduction Diabetes is a significant health problem amongst people with intellectual disabilities, yet there is a lack of qualitative literature looking specifically at their experiences and perceptions of living with this chronic illness. Method Using Interpretative Phenomenological Analysis, this study explored the experiences and perceptions of four people with intellectual disabilities and diabetes. Results Results showed that participants demonstrated some knowledge of the language surrounding diabetes, but considerable confusion and uncertainty about their illness. The impact of diabetes was described in terms of physical, emotional and social consequences, and participants spoke of diabetes in the context of co-existing health problems. Conclusions People with intellectual disabilities and diabetes face many challenges when perceiving and coping with their illness. Gaining insight into these challenges could help health professionals work together more effectively and provide appropriate support to people with intellectual disabilities and diabetes. © 2011 Blackwell Publishing Ltd.