The aim of this study was to define the effects of pregnancy on sexual life. The research was carried out during January-August 2000 at the Antenatal Polyclinic of University of Istanbul, Faculty of Medicine. The sampling consisted of 150 pregnant women in the 34th week or later in pregnancy, who were not restricted in their sexual lives by their physicians, and for whom the risks of placenta previa, early rupture of membranes, and premature birth risk were not present. We gathered the data using an interview form that was developed in the direction of the phases of sexual function (desire, stimulation, plato, orgasm, resolution). The form included 63 questions covering the experiences of pregnant women in all three trimesters of pregnancy. Researchers filled out forms during face-to-face interviews with the pregnant women. Sexual intercourse frequency was noted to decrease as pregnancy progressed. Fear of sexual intercourse was prevalent particularly in the third trimester. The pregnant women experienced less stimulation during sexual intercourse as pregnancy progressed. Length of intercourse also decreased during the later phases of pregnancy compared with prepregnancy. Inability to experience orgasm increased with each trimester. We determined that pregnant women felt more pain during the coitus as the pregnancy progressed. The rate of sexual satisfaction declined as pregnancy progressed, particularly during the third trimester. We determined in our study that sexual functioning declines as pregnancy progresses compared with prepregnancy.