Pregnancy is a special period in which women experience many changes. Negative psychosocial health level and poor prenatal attachment during pregnancy can result in negative maternal behaviors, postpartum anxiety, and depression. This study was conducted as a randomized controlled experimental study which aimed at identifying the effect of pregnancy yoga on the pregnant's psychosocial health and prenatal attachment. Sixty three pregnant women who were primipara, who were in the 14 to 26 weeks of their pregnancy, who did not have any chronic disease and a past yoga experience, and who had singular and spontaneous pregnancy were included in the study. Before the intervention, all the pregnant women were evaluated with Pregnant Information Form (PIF), Pregnancy Psychosocial Health Assessment Scale (PPHAS), and Prenatal Attachment Inventory (PAI). The yoga group did yoga for 40 minutes two days a week for a period of 8 weeks under the supervision of one of the researchers. At the end of 8 weeks (post intervention), both the yoga group and the control group were re-evaluated through the Pregnancy Psychosocial Health Assessment Scale and Prenatal Attachment Inventory. Chisquare, independent sample t test, paired sample t test, Mann Whitney U test and Wilcoxon Signed Ranks were used for data analyses. Post intervention analyses revealed that the mean Pregnancy Psychosocial Health Assessment Scale scores of the experimental group were significantly higher than the scores of the control group (p < 0.001). At the beginning of the study, the Prenatal Attachment Inventory mean scores of both groups were similar. However, at the end of intervention, it was observed that Prenatal Attachment Inventory mean scores of the experimental group were significantly higher than those of the control group (p < 0.05). The mean anxiety and stress subscale score was found to be higher in the experimental group than the score in the control group (p < 0.05). When the mean anxiety and stress subscale score increased, anxiety and stress level decreased. Prenatal yoga is an effective method in in _AA t.,asiog the pregnant's psychosocial health level and prenatal attachment.