Objectives: Prescribing antipsychotic medications to children and adolescents with severe mental and developmental disorders is common; however, there is a lack of consensus on appropriate metabolic monitoring for this population. This review systematically evaluates studies examining metabolic monitoring of children and adolescents prescribed antipsychotic medication to understand the clinical practice of metabolic monitoring and identify opportunities to improve the safety of antipsychotic prescribing in this population. Methods: A systematic search for original research on metabolic monitoring in children and adolescents prescribed antipsychotics was conducted in six databases (PubMed, EMBASE, PsycINFO, The Cochrane Library [Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CENTRAL], Cochrane Methodology Register and Web of Science [Science and Social Science Citation Index]) from inception to February 2020 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were assessed for quality and findings summarised using narrative synthesis. Results: Fifteen papers were identified. Studies agreed on the need for metabolic monitoring; however, there was a gap between guideline-recommended practice and clinical practice. Variable rates of baseline and subsequent monitoring were reported for both physical and biochemical parameters, with particularly low rates for monitoring requiring venesection. Younger age was also associated with lower monitoring rates. Implementation of quality improvement activities (new guidelines, staff education and checklists) improved monitoring rates although the measurement of biochemical parameters still occurred in only a minority of children. Conclusion: Despite widespread awareness and concern regarding metabolic side-effects, monitoring occurred inconsistently and infrequently, particularly for biochemical parameters requiring venesection. Monitoring of anthropometric measures (weight, body mass index and waist circumference) with escalation to more laboratory testing where metabolic concerns are identified may improve monitoring. Minimising iatrogenic harm, through reduced antipsychotic prescription where possible, is a clinical priority in this population.