Abstract: The study explored the determinants of conventional family planning among women of childbearing age within the Sanru project in Kinshasa, The Democratic Republic of the Congo. The Functionalist and Social Marketing theories were applied to the study. Phenomenology research design and non-probability purposive sampling technique were used to select fourteen women and six key informants. Key informants included three community-based distributors (CBDs), one public health professional, one Sanru stakeholder, and one church leader. These data were collected through in-depth interviews, key informants’ interviews, and content analysis, and then analysed using thematic analysis. The findings revealed that religious teachings and practices greatly influenced the use of family planning methods in Selembao. It was established that programmes organised by Sanru did not contribute to clients’ knowledge regarding eligibility criteria, side effects, health complications, and natural family planning. Three recommendations were made. Firstly, it was recommended the implementation of the Government Policy on free counselling and the distribution of family planning methods. Secondly, the study suggested the establishment of a committee in charge of monitoring and evaluating programmes and activities that promote the use of diverse family planning methods. Lastly, the study called for the engagement of the Minister of Gender and Family in the remuneration of CBDs. The study equally advocated for the facilitation of a variety of family planning methods and the establishment of significant training on natural methods. It was anticipated that the research findings could contribute to the improvement of Sanru’s implementation strategies.