Long term complications of chemotherapy treatment in young female patients include loss of fertility and ovarian function, which significantly affects their life quality. The purpose of this research was to demonstrate the methods of fertility preservation in female patients, who suffered from lymphoma and were treated with chemotherapy, with an emphasis on the use of gonadotropin-releasing hormone agonists (GnRHa). Furthermore, the purpose was to assess the efficacy of GnRH agonists in restoring cyclic ovarian function (COF) after treatment. We collected and retrospectively analyzed data from medical records of women (18-40 years), who suffered from lymphoma in the period between 2011 and 2014, and therefore were treated with chemotherapy. The collected data included the type of lymphoma, type of chemotherapy regimen used, menstrual status before, during and after the chemotherapy, and finally, whether the patient used GnRH agonist during the therapy. Based on this, the patients were divided in the GnRHa and the control group. The primary end point was to determine the percentage of patients who maintained COF. Total of 48 patients met the enrollment criteria of the research, while 8 of them were treated with GnRH agonist during the therapy. During the follow-up period (17-63 months), each of 8 patients (100%) in the GnRHa group restored COF, whilst in the control group 80% (32/40) of patients restored it. The difference was not statistically significant (p=0.316). On the other hand, the difference in the median age between the GnRHa and the control group appeared to be significant (p=0.047), with the control group being older. Furthermore, the analysis demonstrated that there was no significant difference in restoring COF, depending on the fact that the patients were over or under 30 years old, whilst the patients treated with eBEACOPP protocol restored COF in smaller percentage (p=0.04), compared with those treated with ABVD protocol. In spite of the fact that 20% more patients in the GnRHa group restored COF after therapy, the difference was not significant, therefore the efficacy of the GnRH agonist was not proven. Still, a small number of patients receiving GnRH agonist could have affected the results, so future research should include more patients receiving this drugs.