It is a retrospective and transverse study with an analysis of results from patients submitted to intrauterine insemination (IIU), intratubal gamete transfer (GIFT) and in vitro fertilization and embryo transfer (FIVTE), at the Clinic of Assisted Reproduction, Instituto Nacional de Perinatología in Mexico City. From 134 cycles of patients submitted to IIU, 113 corresponded to women with diagnosis of sterility from non determined cause, and 21 to cases with endometriosis, and at least one permeable tube. From the first group, 22 pregnancies were obtained, for a monthly fertility rate of 19.4%; and from the second one, 12 pregnancies with a fertility rate of 56%. This, which is very high , may be explained by the relatively small number of cases in the second group, or else, by the influence of a previous medical treatment for endometriosis; the square Chi analysis shows a P less than 0.01 in the two groups. In the GIFT and FIVTE cases, from which 35 cycles were analyzed, per each procedure, there were 10 pregnancies, 9 for GIFT and one for FIVTE; the amount is very limited in order to obtain conclusions, but it seems that there is a proportional tendency in GIFT to less amount of pregnancies in women with endometriosis. The analysis of hormonal follow up did not show differences in the groups, and the averages may be useful to determine, early, the cancellation, or not, of an stimulation cycle. Finally, in FIVTE cases there is a diminution of fertilization index in women with endometriosis (53%), as compared with the cases without disease (80%).(ABSTRACT TRUNCATED AT 250 WORDS)