BACKGROUND Studies indicate that the incidence of young women diagnosed with colorectal cancer is rising, thus there is an increasing number of female colorectal cancer survivors of premenopausal and child-bearing age. Adjuvant FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) chemotherapy is the most widely used standard treatment for stage III and high-risk stage II colon cancer. We evaluated the incidence of FOLFOX-induced amenorrhea in women age 50 and younger treated with adjuvant therapy for colorectal cancer. PATIENTS AND METHODS A search of pharmacy records identified 119 women age 50 or younger who received adjuvant FOLFOX chemotherapy at Memorial Sloan-Kettering for stage II or III colorectal cancer from January 2002 and January 2011. Eligible patients were mailed an anonymous questionnaire. The returned surveys were reviewed and the results tallied. RESULTS Seventy-three patients returned the questionnaire. Twenty-four patients were excluded from analysis: 19 were treated with pelvic radiotherapy, 2 patients had undergone bilateral oophorectomy, 2 had a hysterectomy, and 1 stopped menstruating before diagnosis. Forty-nine patient responses were analyzed. In total, 41% (n = 20) experienced amenorrhea during chemotherapy. Sixteen percent had persistent amenorrhea 1 year after completion of chemotherapy. The incidence of amenorrhea during chemotherapy trended higher in patients aged older than 40 compared with patients aged 40 and younger (59% vs. 31% [P = .075]). There was no statistically significant difference in persistent amenorrhea between the 2 age groups (24% vs. 13%; P = .42). CONCLUSION In this retrospective series, there appears to be a trend toward FOLFOX induced amenorrhea during chemotherapy increasing with age. Twenty-four percent of women older than the age of 40 were found to have persistent amenorrhea after FOLFOX therapy. Because of the small sample size, the study is underpowered to detect a statistically significant difference between older and younger patients. Prospective studies are planned to further characterize the effect of FOLFOX on early menopause and fertility.