To investigate the effectiveness of interventions that aim to improve the mental health of mothers of children with disabilities. Seven databases were searched. Interventions incorporated primarily cognitive-behavioural, psychoeducation, mindfulness or support-group approaches. The Template-for-Intervention-Description-and-Replication guided descriptions. Meta-analyses using a random effect model of randomized controlled trials assessed intervention effects on parenting stress and mental health. Of the 1591 retrieved papers, 31 met criteria to be appraised and 17 were included in the meta-analysis. Cognitive-behavioural approaches reduced parenting stress [2 studies, n = 64, pooled Standardized-Mean-Difference (SMD) = 0.86, 95% CI (0.43, 1.29)] and improved mental health [3 studies, n = 186, pooled SMD = 1.14, 95% CI (0.12, 2.17)], psychoeducation approaches improved mental health [2 studies, n = 165, SMD = 0.60, 95% CI (0.17, 1.03)]. Cognitive-behavioural and psychoeducation interventions are effective. Further research and clinical guidelines are warranted.