Background In recent years, natural cycle IVF has been undergoing a revival, gaining recognition as a safer, cheaper, and more comfortable option for patients. we define natural cicle IVF as the treatment in which oocytes are obtained from a spontaneous ovulatory cycle. When oral drugs are used (usually clomiphene citrate or letrozole), the process is referred to as modified natural cycle IVF. The aim of this study is to clarify whether the introduction of oral medication is beneficial for patients. Methods We retrospectively analysed all natural or modified IVF treatments that took place in our clinic during the studied period (January 2016 - December 2020). Descriptive variables were analysed with a t-test, and a chi-square test was performed on result variables. Results We found significant differences in the number of oocytes obtained after oocyte retrieval was (1.03 vs 1.63, p<0.001), number of mature oocytes (0.9 vs 1.3, p < 0.01), fertilization rate (0.7 vs 1.1, p < 0.01), and number of embryos available for transfer (0.5 vs 0.7, p < 0.01).However, we did not found signficant differences in terms of pregnancy rate (26,3% vs 19,6%, p=0.251) or live birth rate (16.3% vs 14,3%, p=0.7806) Conclusions although the numbers of oocytes and embryos available were higher in the group that used oral medication (which is similar to that obtained in previous studies), we did not find any differences in success rates in terms of pregnancy or live birth rate. Adding oral medication to natural cycle IVF, although reducing cancellation rates, does not seem to have an impact on the clinical results of the cycle. More studies are necessary, but we could reconsider the need to add oral medication since they suppose a higher cost for the patient.