This review reports the incidence of hyperprolactinemia, its relationship with genotype, and prolactin-related side effects in children and adolescents treated with antipsychotics. Data on prolactin levels were available for haloperidol, pimozide, risperidone, olanzapine, clozapine, ziprasidone, and quetiapine. Twenty-nine studies were selected after a literature search in the English Medline/Embase/Psychinfo/EBM databases (1965 to August, 2008). All antipsychotics, except clozapine, ziprasidone, and quetiapine, increase the mean prolactin level from baseline values of 8.0 ng/mL to 25-28 ng/mL after 4 weeks of treatment (reference range 0-15 ng/mL). The most and best data are available for risperidone. Five risperidone studies (n = 577) show an increase of prolactin level from 7.8 ng/mL to 17.7 ng/mL after 1 year of treatment, and two risperidone studies (n = 60) show an increase from 7.4 ng/mL to 24.9 ng/mL after 2 years of treatment. Aggregated over all antipsychotics, prolactin-related side effects, such as gynecomastia, galactorrhea, irregular menses, and sexual dysfunction, were reported by 4.8% of the children and adolescents. No data are available on bone mineral density in relation to antipsychotic-induced hyperprolactinemia in children and adolescents. Prolactin levels may be influenced by the genetic differences that influence prolactin metabolism and D2 dopamine receptor density. Persistent elevation of prolactin for periods up to 2 years has been documented in maintenance treatment with risperidone. Very limited long-term data of pimozide, olanzapine, and quetiapine prohibit drawing conclusions for these antipsychotics. Systematic long-term observational studies, including specific questionnaires as well as physical examination, are needed to investigate prolactin-related side effects of antipsychotic treatment in children and adolescents.