BACKGROUND Primary ovarian failure is reportedly increasing in recent years. Environmental factors have been frequently implicated as responsible for this increase, However, only a few of the environmental factors have been proven to cause the ovarian failure in human. METHODS: In June 1995, 24 female laborers, who worked in a factory which used Solvent #5200 (with a main chemical component being 2-bromopropane), developed symptoms of amenorrhea or irregular menstruation. All subjects underwent laboratory tests including measurement of serum LH, FSH, and estradioL Magnetic resonance imaging and ultrasonography of the pelvis were performed in all subjects. Laparoscopic examination was performed in 6 out of 24 patients after obtaining informed consent and 4 of 6 underwent ovarian biopsy. RESULTS: One subject was excluded because she had undergone hysterectomy previously. Among the remaining 23 subjects, 14 and 9 complained of amenorrhea and irregular menstrual periods, respectively. When we defined primary ovarian failure as FSH>30mIU/mL, all of those 14 patients with amenorrhea could be classified as primary ovarian failure. On the other hand, those 9 patients with irregular menstruations had normal FSH levels. Pathologic examination of ovaries showed interstitial fibrosis, loss of primordial follicles, and development arrest of follicles in the group with amenorrhea, similar to what is found in those who received chemotherapy or were exposed to radiation. CONCLUSION: The female laborers who were exposed to the solvent with 2-bromopropane developed primary ovarian failure. This failure was associated with longer duration of exposure. To our knowledge, this is the first report in the world indicating 2-bromopropane as a possible agent for ovarian failure.