Background: People with intellectual disability have substantially more unidentified health needs than the general population. We systematically reviewed the effectiveness of primary healthcare interventions intended to increase health actions for people with intellectual disability. Methods: Electronic databases were searched on 16 September 2014. Randomised and non-randomised studies with a concurrent control group were identified. Study quality was assessed and, where possible, meta-analysis was undertaken. Results: Five studies (3 randomised controlled trials, 1 matched cohort study, and 1 cohort study) with a total of 1,570 participants were included. General practitioner-led health checks were the most effective intervention and resulted in significantly more clinical activities, such as vision testing (risk ratio [RR] = 3.3, 95% CI [2.3, 4.7]) and hepatitis B vaccinations (RR = 2.4, 95% CI [1.7, 3.4]). Conclusions: Health checks were the only intervention to significantly increase short-term health promotion and disease prevention activity. The long-term effect of any intervention remains unknown.