Breastfeeding is a natural process in the mother's reproductive cycle that needs to be maintained for its quality and continuity for 2 years since the baby is born. Postpartum psychological changes and feelings of not being able to breastfeed properly encourage an increase in adrenaline production which follows maternal anxiety and increases adrenaline so that it suppresses the activity of oxytocin and prolactin to produce breast milk. The purpose of this study was to determine the effect of oxytocin stimulating massage (PSO) on reducing maternal anxiety and smooth milk production. The research design used a quasiexperimental without control. The sample is 27 people, using a random sampling technique. The research was conducted in the working area of the Cihideung Public Health Center, Tasikmalaya, Indonesia. The results showed that there was a significant difference in the average anxiety score of breastfeeding mothers between before and after PSO therapy (r = 0.0001 (r < 0.05)) and there was a significant difference in the average percentage of smooth milk production in breastfeeding mothers between before and after PSO therapy (r = 0.0001 (r < 0.05)).