OBJECTIVE: TO evaluate the use of calcium supplementation in the treatment of premenstrual syndrome. DATA SOURCES: Clinical literature accessed through MEDLINE (from January 1967 to September 1999). Key search terms included calcium, PMS, and premenstrual. DATA SYNTHESIS: Up to 50% of women experience some form of premenstrual syndrome. An evaluation of studies focusing on calcium in the management of premenstrual symptoms was conducted. CONCLUSIONS: Calcium supplementation of 1200–1600 mg/d, unless contraindicated, should be considered a sound treatment option in women who experience premenstrual syndrome. The supplemental dose of calcium can be adjusted downward in the few patients who routinely consume large quantities of calcium in their diet.