Prenatal yoga aims to prepare pregnant women physically, psychologically and spiritually in the face of childbirth. The purpose of the study was to determine the effectiveness of attending prenatal yoga classes on the mental health of pregnant women. This study uses a mixed method with a quantitative explanatory strategy, posttest-only control design to determine the effect of participating in prenatal yoga classes and semi-structured interviews to explore the mental health condition of pregnant women and coping mechanisms. This research was carried out at Bidan Delima Clinic, East Banjarmasin. The population and sample of this study were pregnant women in the working area of Bidan Delima Clinic, East Banjarmasin. Based on the results of quantitative analysis, there were significant differences in mental health conditions between the control group and the treatment group (p < 0.05). Qualitatively, the autonomic component (autonomous) of pregnant women experienced a decrease in physical disorders, the behavioral component (behavior) of pregnant women experienced a decrease in laziness, reduced complaints, and increased mood, the cognitive component (cognition) of pregnant women experienced sleep disturbances, decreased feelings of anxiety and difficulty concentrate Coping mechanism used by pregnant women is to get support from husband, family, and social environment. Prenatal yoga classes are very effective for mental health in pregnant women. There needs to be early treatment of maternal mental health problems so that negative impacts can be reduced.