Background: Creating a stable and long-term relationship also called “longitudinality” between the population and general practitioners is crucial for the family physician program. Constant change of family physician can deteriorate longitudinality. In this study we aim to reveal what factors people usually take into account when it comes to choosing a new family physician or changing their current family physician.Method: A qualitative study with content analysis approach and case study was carried out in Ilam province, Iran, in 2019. Purposeful sampling with maximum variations was followed to select the key. Data was analyzed and main themes of framework were extracted by using MAXQDA software. Results: The content of interviews was categorized in two main themes, 6 sub-themes and 38 codes. General behaviors, social and physical characteristics, professional expertise, and pharmaceutical prescriptions of family physician and also location and physical features and properties of the health center were the main sub-themes extracted from interviews which can influence the people’s choice of family physician.Conclusion: Some of the factors extracted from the interviews may have different effect on the choice of different people with different demographics. For instance, different patients may have different ideas about the age, gender, years of medical practice, language and origin of birth place of doctors. Quantitative studies are needed to rank the factors identifies in this study according to their significance for choosing FP and reveal preferences of patients for each factor.