Objective: After the improved long-term survival in young women with cancer undergoing chemotherapy, the preservation of their future fertility has been the focus of recent interest. We studied whether gonadotropin-releasing hormone (GnRH) analogs could prevent the early onset of ovarian insufficiency post-chemotherapy and protect fertility. Methods: The patients were divided into two groups. Group A consisted of post-menarche patients aged 12–45 years ( n = 15), who received chemotherapy but no GnRH analog protection. Group B consisted of post-menarche patients aged 12–45 years ( n = 15), who received chemotherapy with GnRH analog. The gonadotropin values in the two groups were checked. Both groups received a multi-agent chemotherapy regimen (bleomycin, etoposide, cisplation, Taxol, carboplatin), (Taxol, cisplatinum) and (vincristin, actinomycin, cyclophosphamide) In group B, the GnRH analog was diphereline (3/75 mg). It was administered each month before and during treatment with chemotherapy. The first dose was administered 7 days before starting chemotherapy. Result: In group A, five patients (33%) had amenorrhea and premature ovarian failure. The laboratory values in these five patients showed increased gonadotropin. In group B, the most of patient resumed menstruation after 2–4 months. All these patients had a normal titer of gonadotropin. Conclusion: The GnRH analog co-treatment should be considered in every woman of reproductive age receiving chemotherapy. [ABSTRACT FROM AUTHOR]