12 couples, with infertility due to male subfertility, female antisperm isoimmunization, male antisperm autoimmunization, cervical mucus insufficiency or unexplained infertility underwent intrauterine A.I.H. with capacitated sperm and controlled ovarian stimulation. The pregnancy percentage was of 41.6% per woman treated and of 31.2% per treatment cycle; five pregnancies were obtained, of which two resulted in abortions. Five cases of oligoasthenospermia were treated, three severe and two moderate; two pregnancies occurred in the former and one in the latter. S.I.T. and S.I.T.-cap. were performed on the serum, and Micro-S.I.T. and Micro-S.I.T.-cap. on the cervical mucus in order to exclude the possibility that intrauterine A.I.H. with capacitated sperm might have caused capacitated or non-capacitated antisperm immunization. Intrauterine A.I.H. would seem to be a useful alternative to G.I.F.T. and to I.V.F./E.T. or at least a technique which should be performed before these two in cases of infertility not caused by female organic pelvic disease; it is cheap, simple and extremely well-accepted by the patient.