This paper presents a systematic review of the evidence on the effectiveness of mindfulness for people with intellectual disabilities. Primary studies published in the English language between 1980 and 2012 were identified from electronic databases, experts and citation tracking. Eleven relevant studies evaluating mindfulness training and practice were identified: seven studies with people with intellectual disabilities, two studies with staff members or teams and two studies with parents. The studies found improvements in aggression and sexual arousal for people with intellectual disabilities after mindfulness training. Training staff led to benefits for people with intellectual disabilities, decreased use of physical restraint for aggressive behaviour and increased job satisfaction. Training parents led to improved parental satisfaction and well-being and improved parent–child interactions. The reported positive findings suggest that service providers, people with intellectual disabilities and their families may want to consider mindfulness approaches. However, the findings have to be interpreted with caution due to methodological weaknesses identified in the studies. Further high-quality independent research is needed before the reported improvements can be more confidently attributed to mindfulness.