Introduction: The evaluation of Ph.D. students is one of the main parts of their curriculum, and the comprehensive exam is held with the aim of evaluating the abilities acquired in the educational stage and verifying the qualification and ability to carry out research activities. The purpose of this research is to identify the challenges of holding the comprehensive exam of Ph.D students in the medical sciences universities (Iran) and to provide appropriate suggestions.
Methods: The research approach was qualitative and the research method was conventional content analysis (inductive) and the type of study was applied. Participants included the members of the board of examiners in each specialized field with different positions and degrees, Ph.D. students who passed the comprehensive exam, as well as educational staffs in the 7th area of health education like Isfahan University of Medical Sciences, Kashan University of Medical Sciences, Yazd University of Medical Sciences and Shahrekord University of Medical Sciences.  Sampling was Purposive and heterogeneous with maximum diversity to obtain different views. In the present study, after 17 interviews, no new data was obtained; however, to be sure, 3 other participants were also interviewed (20 participants). Graneheim and Lundman's 5-stage model was used for data analysis, and Lincoln and Guba criteria were used to measure the trustworthiness of data.
Result: The data were classified in 41 codes, 9 subcategories and 3 main categories in the challenges section and in 48 codes, 13 subcategories and 3 main categories in the solutions section. The main concepts about the challenges of conducting a comprehensive Ph.D. exam including macro-policy and planning, the limitations of laws and weak planning, and the problems of the people involved in the exam, as well as the main concepts about the solutions to optimize the conduct of a comprehensive Ph.D exam, including solutions before entering students for the Ph.D course, the solutions related to the comprehensive exam, and the solutions related to the duration of the Ph.D course.
Conclusion: The challenges of holding a comprehensive exam for Ph.D students in health are multifaceted and require a comprehensive approach to address them. By carefully paying attention to these challenges and implementing solutions at the micro and macro levels, the educational system can better achieve the main mission and goal of holding the comprehensive and at the same time evaluate the students' readiness to enter the research course more accurately.