OBJECTIVE: Implantation window (IW) remains one of the most important challenges in Reproductive Medicine. Several clinical trials have been developed with the aim to assess the possible effects of different techniques in increasing the implantation rate. However, it hasn’t been found any evidence statistically significant at the moment, as is the case of the Endometrial Scratch (ES). Endometrial Immunological Profile (EIP) has also been studied as a possible mechanism involved in the implantation stage and its treatment (when an alteration is diagnosed), is claimed to improve pregnancy rates. Our aim was to evaluate the effect of a specific treatment for EIP in patients undergoing an egg donation cycle (including steroids, luteal Hcg, pentoxifiline, vitamin E and high progesterone doses) compared to another group of patients who underwent an endometrial scratch, in terms of pregnancy rate. DESIGN: We retrospectively reviewed from Jan 2014 to Dec 2016, 69 egg donation cycles: 19 with EIP and specific interventions and 50 patients with ES performed the cycle prior to embryo transfer. MATERIALS AND METHODS: We analysed their results in terms of pregnancy rate (PR) and compared basal characteristics. All patients were prepared for the embryo transfer with the conventional oestrogen plus progesterone protocol. Those patients in the EIP group received the specific treatment according to the immunological profile, performed 1 to 6 months before the embryo transfer. Patients in the ES group were performed an endometrial scratch 3 to 6 weeks before the embryo transfer. RESULTS: Patients in both groups had comparable endometrial thicknesses after their preparations (Mean 8.37mm for EIP and 7.87mm for ES, p¼0.23). The proportion of D3 and D5 embryos was equivalent in both groups (73% for EIP group vs 74% for ES). The overall PR was higher but not statistically significant in the ES group compared to the EIP group (48,0% Vs. 42,1%, P¼0,14). Nevertheless, the average embryo quality was significantly higher in the ES group (A quality embryos in EIP group 13.0%, A quality embryos in ES group 53.6%, p¼0.03), what may be a confounding factor for the previous results. In addition, the number of days between the endometrial biopsy for inmunological assessment and the embryo transfer (Mean¼159,2) was significantly higher than the number of days between the endometrial scratch and the embryo transfer (Mean¼40,9). CONCLUSIONS: Our retrospective study was unable to detect any differences between patients treated with endometrial scratch or a specific immunological treatment, after the diagnosis of implantation failure. Our results have to be carefully analysed as there is a limited number of cases and the design of this study is retrospective. Thus, further studies are required to assess the possible effect of endometrial scratch or immunological therapy.