Traditional practices and knowledge of plants are useful for the improvement of livelihoods. The loss of traditional knowledge concerning the use of plant resources has become a serious issue. Myanmar is one of the hotspots of biocultural diversity, and an accurate understanding of the diversity of plant use is urgently required. The objective of this study, by using ethnobotanical techniques, is to compile a checklist of medicinal plants used for postpartum care by Kayin Ethnic People and to document traditional knowledge and practices of these plants in the study area. Field surveys were carried out at eight villages located in Taungoo, Bago, Tharyarwady, Pyay District of Bago region, and Pha-An District of Kayin State, Myanmar. Group discussions, unstructured interviews, and collection of specimens were conducted with the local people. Four common species, Blumea balsamifera (L.) DC., Celastrus monospermus Roxb, Croton persimilis Müll.Arg., and Rotheca serrata (L.) Steane & Mabb. which were used for postpartum care were recorded. A trend of traditional knowledge loss has been observed in the study area, which calls for the promotion of knowledge transmission to younger generations.