The effects of methylxanthines (caffeine, theophylline and theobromine) on the symptoms associated with fibrocystic breast disease were studied in 147 patients. Disease was documented by mammography, physical examination and clinical symptoms. Only those individuals with breast pain (n = 138) were included in the study. Questionnaires were presented and explained to all patients by the same nurse examiner. Patients reported their degree of caffeine consumption as either light (two cups per day or less of caffeine-containing beverages or foods), moderate (more than two cups, but less than six cups per day), or heavy (six cups per day or more of caffeine-containing products). They additionally reported breast pain as mild, moderate or severe. Past medical and family histories were reported as well as medication intake. All patients were counseled to abstain from or reduce caffeine consumption and were given a list of commonly used caffeine-containing products. The results at the end of one year indicated that compliance was high, with 113 patients (81.9 percent) reducing their caffeine intake substantially and, of those, 69 (61 percent) reporting a decrease or absence of breast pain. This study supports the findings of others in that caffeine restriction is an effective means of management of breast pain associated with fibrocystic disease.