Summary: We investigated the effect of the sperm-cervical mucus penetration tests (SPT) on the fertilization rate (FR) and pregnancy rate (PR) in patients treated with either in vitro fertilization (IVF) or ovulation induction combined with intrauterine insemination (OI+IUI). Infertile couples where the women had normal ovarian function and a normal pelvis at laparoscopy and her partner had normal seminology who had failed at least 2 SPTs were treated with either IVF or OI+IUI. These patients were compared with similar couples in whom SPTs were satisfactory (SPT+ve). Group A (SPT+ve) consisted of 46 patients who underwent 78 treatment cycles of IVF and Group B (SPT-ve) comprised 31 patients who underwent 35 IVF cycles. Group C (SPT+ve) consisted of 39 patients who underwent 84 treatment cycles with OI+IUI, and Group D (SPT-ve) consisted of 15 patients who underwent 37 cycles witfi die same treatment. In patients treated with IVF, the FR and PR per embryo transfer were 77.0% and 20.0% respectively in Group A, and 64.0% and 22.6% respectively in Group B. The difference in FRs was statistically significant (p>0.001) but there was no difference in die PRs. In patients treated with OI+IUI, the PR per cycle were 22.0% in Group C and 16.2% in Group D. These results indicate that SPT failure was associated with a lower FR in IVF but this did not affect the PRs. Similarly there was no difference in PRs following OI+IUI.