This study aimed to synthesize the primary care service provided by a Public Health Center (PHC) of Health Department under the Bangkok Metropolitan Administration. Objectives of this study were to explore the ratio of the people who received and did not receive the service from the PHC, to propose the PHC Family Medicine Service Model based on the Ministry of Public Health Reform Policy which relevant to the BMA context in terms of professional competencies, Information technology system, financial regulations which reflects the principles of transparency, and good governance. Moreover, the proposed service model should also take into account the possible public health networks in the area such as a drug store and the private hospital or private health service center. Mixed method research method design was applied in 4 pilot public health centers included PHC 29, PHC 30, PHC 60 and PHC 66. Data collection at each center included 7 in-depth interviews with public health staff, 4 face to face interviews with 100 patients and 30 family members who attended services from the center, 50 family members who did not seek services from the center, 30 people who worked in the one kilometer radius of the PHC and attended service from the PHC. Significance findings revealed that people who attended the PHC service due to the close distance and easy to travel to the PHC. In addition, they also perceived that the PHC provided health promotion service, immunization, emergency care for a minor injury. However when comparing with people who live in the area, data revealed that percentage of people who seek these same services in the hospital are still higher than those who come to PHC. The four PHCs included in this study are the pilot PHC. Despite the same principles and policy, each center has offered in three different service models due to the different socioeconomic and cultural context. As the result, this study proposed a “service model” which provides services based on the information from the Central Information System which also connects with a private hospital and a drugstore in the catchment area. Moreover, the service model must create the network with all organizations and mobilize them to promote health of their people via intervention such as nutrition, exercise, etc. in concordance with the world health organization strategy on “Health in all Policies” and connects with the Quality of Life District Committee mechanism. To facilitate this service model, the supporting system has to be established in at least three mechanisms: an information management system, capacity building system for PHC staff, and a transparent financing system with good governance mechanism. Recommendation can be drawn as follows: Factor influencing health seeking behavior of the Bangkok people included distance and convenience to travel, perception of the types and quality of service. Therefore, public relation activities through social media and word of mouth to promote services provided in each PHC should be done; PHC Professional skills especially in technical skill such as documenting and evaluating the service, service process improvement, and digital information technology development and management need to be enhanced. Moreover the financial call center unit for PHC administrative staff should be set up.