Background. The fears, concerns, and negative attitudes of pregnant women towards sex during pregnancy can have a negative impact on the sexual relationship and sexual performance of couples. Objectives. We aimed to determine the effects of cognitive-behavioral counseling on misconceptions about sexual intercourse during pregnancy in pregnant women. Material and methods. In this randomized educational study, five clinics were randomly selected in Arak, Iran. A total of 20 pregnant women who met the inclusion criteria were selected from each clinic. The Misconceptions about Sexual Intercourse during Pregnancy Questionnaire (MSIP-Q) was completed after written informed consent. Finally, twenty-two women with the lowest scores on the MSIP-Q were selected. Eleven subjects were allocated to the intervention group (cognitive-behavioral counseling), while eleven subjects were assigned to the control group. The questionnaire was also completed by the participants over a three-month interval. For statistical analysis, descriptive and inferential statistics (student's t-test, paired t-test and Fisher exact test) were calculated using SPSS software. Results. The mean MSIP-Q score was 77.81 ± 10.03 in the intervention group and 71.27 ± 8.29 in the control group before the intervention; no significant difference was found between the groups. On the other hand, the mean MSIP-Q score was 113.3 ± 11.16 in the intervention group and 76.90 ± 19.07 in the control group following cognitive-behavioral counseling; a significant difference was found between the two groups (p < 0.001). Based on the findings, no significant difference was reported in the intervention group in the three-month follow-up; in fact, the effects of training remained stable. Conclusions. This study showed that there are misconceptions about vaginal intercourse during pregnancy in Iranian women. Therefore, providing sexual health services and training during pregnancy are necessary at health clinics.