Purpose: The workload and working time of health care workers have become a critical issue in Taiwan, and attracted a lot of attention not only from health care workers, but also the general public as well as health care authority. Few studies investigated the stressors that physicians encounter in their daily clinical practice in Taiwan. This study aimed to investigate the stressors that physicians perceive. Methods: We conducted a qualitative study using focus group interviews to examine the stressors. Criteria sampling was used based on the following criteria: (1) having an experience of clinical practice for more than four years; (2) from self-owned primary care outpatient clinics, or from medical centers. All of the interviews were taped then transcribed into transcription notes. All the transcription notes and field notes were the data for analysis in this study. A co-principal investigator and a research assistant, both having several years of experience conducting qualitative studies, were responsible for data analysis. Results: We identified a variety of stressors (i.e. job stress, interpersonal relationships, financial stress, academic stress, career planning, etc.) which were highly associated with the three core stressors we derived from the transcripts (physician-patient relationship, intention to achieve excellence, and system regulation). Conclusions: This study of focus group interviews showed three core stressors accounting for the various stressors in physicians' daily clinical work: physician-patient relationship, intention to achieve excellence, and system regulation. The three core stressors are highly correlated with other stressors such as job stress, interpersonal relationships, financial stress, academic stress, and career planning.