Hysterosalpingography is one of the essential diagnostic methods for examining women who have difficulty becoming pregnant. This procedure is somehow invasive and is associated with numerous complications such as allergic sensitivity, pain, abdominal cramps and shock. Therefore, this study aimed to investigate the effect of evening primrose on cervical length and pain during and after hysterosalpingography. In this double-blind clinical trial, 66 candidates for hysterosalpingography were randomly divided into two groups. A group received 1000 mg of evening primrose orally for two days prior to hysterosalpingography, while the control group received a placebo drug similar in size to evening primrose three days prior to hysterosalpingography. The pain level was recorded based on the Visual Analogue Scale (VAS), during tenaculum placement but also immediately and four hours after hysterosalpingography. Finally, the data were analyzed using SPSS (version 20). There was a significant difference between the two groups in terms of pain during insertion of speculum and injection of the contrast medium (p <0.05). Less pain was reported in the evening primrose group compared to placebo. There was no significant difference between the two groups in terms of the length and diameter of the cervix (p <0.05). Given the fact that it is a medicinal plant with no complications and can reduce pain during speculum insertion and during contrast medium injection, evening primrose seems to be a good drug for managing pain during hysterosalpingography.