The diagnostic value of hysterosalpingography remains unquestioned. Previous studies have suggested that patients who underwent hysterosalpingography with an oil-soluble contract medium (OSCM) rather than a water-soluble contrast medium (WSCM) had higher subsequent fertility rates. This study evaluated subsequent fertility rates in 339 patients who underwent hysterosalpingography in which OSCM or WSCM was used. All forms of infertility were included and over-all, pregnancy occurred in the WSCM group in 21 of 162 patients (13%), in the OSCM group in 51 of 177 patients (29%); these rates were significantly different (P less than 0.001), with the unexplained infertility group and the male factor infertility group showing the most significant difference. Adverse effects of OSCM hysterosalpingography were not corroborated. For this reason it is suggested that initially the patient undergo hysterosalpingography with WSCM. Once patency has been established, 3 ml of OSCM should be injected as a therapeutic modality to increase subsequent fertility.