There is increasing use of antipsychotic drugs in pediatric and psychiatry practice for a wide range of behavioral and affective disorders. These drugs have prominent side effects of interest to pediatric endocrinologists, including weight gain and associated metabolic risk factors and hyperprolactinemia. The drugs block dopamine action, thus disinhibiting prolactin secretion. Hyperprolactinemia is especially prominent with first-generation antipsychotics such as haloperidol and the second-generation drugs, most commonly risperidone, with some patients developing gynecomastia or galactorrhea or, as a result of prolactin inhibition of gonadotropin releasing hormone from the hypothalamus, amenorrhea. With concern about the long-term effects of antipsychotics on bone mass and pituitary tumor formation, it is prudent to monitor serum prolactin levels in antipsychotic drug-treated pediatric patients and consider treatment with an agent less likely to induce hyperprolactinemia.