Hyperprolactinemia may be a concern in the treatment of patients with schizophrenia. The side effects associated with high prolactin levels can have a negative impact on patient compliance with treatment. Atypical antipsychotics as a group cause less hyperprolactinemia than conventional antipsychotics, yet there is considerable variation among specific drugs. Risperidone at higher doses has been shown to produce increases in prolactin similar to conventional antipsychotics. At the other end of the spectrum, clozapine and quetiapine produce minimal sustained increases in prolactin that are no different from placebo. However, correlations between prolactin elevations and clinical symptoms have not been well-established. This paper reviews the published literature regarding prolactin levels in treated and untreated patients with schizophrenia and the relationship of prolactin and dopamine. It concludes with an overview of the effects of specific atypical antipsychotics on prolactin levels in patients with schizophrenia.