Sarcopenia is defined as a syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength. It has hardly been studied in older people with intellectual disabilities (ID). In this study 884 persons with borderline to profound ID aged 50 years and over, were investigated to determine the prevalence of sarcopenia in this group. To identify the associations of sarcopenia, logistic regression analyses were performed with patient characteristics, mobility, physical activity, intake of energy and proteins, body mass index (BMI) and levels of CRP, albumin and vitamin D in serum. The prevalence of sarcopenia was 14.3% in the total group. In the age group 50-64 years prevalence was 12.7%. Sarcopenia was positively associated with mobility impairment and inflammation and negatively with BMI. The next thing to do is collecting longitudinal data to study the relation between sarcopenia and negative outcomes in older people with ID. (Contains 4 tables.)