This study entitled with mother support group in PMTCT services was conducted atrnAmbo Hospital. The main objective of the study was to explore and describe the role and relatedrnactivities of mother support group in PMTCT services. Descriptive case study method was usedrnto conduct such type of qualitative study. Participants of the study included were members ofrnMSG, HIV positive pregnant and post partum women, and health professionals. The participantsrnwere selected through non probability sampling method, using purposive sampling techniquernaccompanied by setting criteria. In-depth interviews and key informant interviews were used torncollect data from the participants. In addition, observations were conducted to substantiate therndata. The analysis started with transcription and translation of the data. Codes had been givenrnbased on participant answers, ideas, and meanings in relation to in-depth interview guide andrnkey informant interview questions. The identified themes were examined against the statedrnresearch questions and research objectives. The final themes were developed through comparingrninitially stated propositions against the research findings. To enhance the rigor of the datarnmechanisms like familiarity with the culture, rapport building, and triangulation were applied.rnThe study conducted according to social work ethical guide-line using consent form.rnThe findings revealed that MSG primarily established to share their experiences tornsimilar peers. Provision of PMTCT education, and psycho social support during ante-natal care,rndelivery and post partum care were the main services provided by MSG. Improvement ofrnknowledge and skill on PMTCT, and infant and young child feeding practice, decrease of stigmarnand discrimination, increment of partner disclosure, increase of uptake of ARV, ante and postnatalrncare, decrease of work burden of clinicians, and low level of mother to child transmissionrnwere the main benefits of the services, and made the services is contributing to PMTCT services.rnLack of continues training for MSG, absence of income generating activities, and lowrnprofessional support were major challenges of services. The study has implication for socialrnworkers, maternal and child health programs and policies as to inculcate engagement ofrncommunity members in different steps of their activities