BACKGROUND Intracytoplasmic sperm injection (ICSI) is highly effective for the control of male factor infertility. The sperm selected for ICSI may have structural abnormalities undetectable to 400x as nuclear vacuoles, decreasing rates of pregnancy and implantation. Recent studies show that with intracytoplasmic morphologically selected sperm injection (IMSI), at higher magnification (> 6,600x), increases pregnancy and implantation rates in patients with repeated failure to ICSI. OBJECTIVE To compare the results of the injection of selected motile sperm organelle morphology examination (MSOME) for IMSI, instead of the use of ICSI in patients with repeated failure to ICSI. METHODS Prospective, observational cohort study. Since February 1, 2010 was administered IMSI to couples with at least two failed cycles of ICSI, and analyzed the first 30 cycles in patients under 38 years of good ovarian reserve. This study group was compared with the last 30 cycles of ICSI performed before that date, in patients with similar clinical characteristics. The IMSI was performed with a magnification of 7,676 increases for evaluation and sperm selection. RESULTS The groups had similar clinical characteristics. The pregnancy rate with IMSI was better than with ICSI (63 vs. 50%), the difference was not significant for the size of the sample, although the trend is clear and clinically significant in favor to IMSI. The implantation rate with IMSI (44.8%) showed statistically significant differences vs. ICSI (29.7%). No significant differences in abortion rates. CONCLUSIONS IMSI significantly improves the implantation rate in patients with repeated failure to ICSI.