This study aims to develop and evaluate an effective problem-based learning model for teaching Pancasila and Citizenship to adults. Considering that adult learners have diverse age and occupational backgrounds, an appropriate learning approach is needed to achieve the educational objectives of Pancasila and Citizenship uniformly for all citizens. This research employs a mixed-method approach, combining qualitative and quantitative techniques through research and development (R&D) methods. The study was conducted in two stages: a preliminary study and an experimental study. Data sources consisted of primary and secondary data, with the research location in Tanjungpura, West Kalimantan. The study subjects comprised 40 adult learners, eight tutors, and three program managers of Pancasila and Citizenship education, selected using purposive sampling.