Objective To investigate the clinical efficacy of acupuncture in treating dyssomnia in children with mental retardation. Methods Sixty patients with mental retardation (4-6 years old) were randomly allocated to treatment and control groups, 30 cases each. The control group received routine rehabilitation therapy (family training guidance, and aetiological, psychological and behavioral intervention) and the treatment group, acupuncture in addition. Sleep latency, rapid eye movement (REM) sleep state and sleep efficiency were monitored by polysomnography in the two groups of patients. The clinical therapeutic effects were compared between the two groups. Results The total efficacy rate was 93.3%in the treatment group and 73.3%in the control group;there was a statistically significant difference between the two groups (P<0.05). There were statistically significant differences in pre-/post-treatment sleep latency, REM sleep state and sleep efficiency difference values between the treatment and control groups (P<0.05). Conclusion Acupuncture is an effective way to treat dyssomnia in children with mental retardation.