ABSTRACT: INTRODUCTION:Sexual function and frequency can change between couples during pregnancy and postpartum, with a decline in sexual function in women. AIM:To investigate sexual function in couples during pregnancy and postpartum. METHODS:This questionnaire-based cross-sectional descriptive study solicited data from 551 couples, 127 (23%) of whom responded: 15 during the first trimester; 26 during the second trimester; and 21, 22, 21, and 22 at 1, 3, 6, and 12 months postpartum, respectively. The Female Sexual Function Index (FSFI) and International Index for Erectile Function (IIEF) questionnaires were used for female and male participants, respectively, and included questions about delivery, breastfeeding, partner's contribution to housework, and desire to have more children for women, and about aspects of their partner's pregnancy and postpartum life for men. Data about maternal/paternal age, parity, body mass index, and mode of delivery were also collected. MAIN OUTCOME MEASURE:FSFI and IIEF total and subcategory scores with attributable factors. RESULTS:The total and subcategory scores related to female and male sexual functions were lowest at 1 and 3 months postpartum, with 79 women reporting female sexual dysfunction (score <26.55). The FSFI subcategory scores (except desire and satisfaction) differed between 1 and 12 months postpartum. The IIEF scores showed no significant differences. The total mean IIEF scores were 17.9 ± 9.6 and 54.9 ± 12.0 in men with and without erectile dysfunction (ED), respectively. The FSFI scores were 8.6 ± 7.2 and 18.2 ± 8.6 in women whose partner had and did not have ED, respectively. No significant differences (P = .76) were observed between the male satisfaction subcategories. CONCLUSION:Sexual function decreased around the time of delivery for men and women, but did not correlate with the sexual satisfaction of men. Type of delivery, breastfeeding, intimacy, and partner's contribution to housework did not affect sexual dysfunction. Saotome TT, Yonezawa K, Suganuma N. Sexual dysfunction and satisfaction in Japanese couples during pregnancy and postpartum. Sex Med 2018;6:348-355.