Introduction: the motivations and reasons for choosing a specialty field among medical students that  a can be effective on training of physicians and promoting   health in the community.

Methods: In a cross-sectional study we investigate   factors influencing
specialty choice of 429 medical residents in Ahvaz Jundishapur
University of medical sciences. Data was collected by a questionnaire with 28 items. The content validity was evalated  by experts and its construct validity was examined using factor analysis.  Its reliability Confirmed through Cronbach’s alpha (0.810). The data was analyzed by SPSS software and analytical statistical methods.

Results: Two hundred twentyparticipants (52.4%) were males.
According to the study , the most effective reason to choose a specific field was to give better public service with 4.33±0.7(out of a total 5) 
followed by personal interest  with 4.15 ± 0.8 and 3.98 ± 0.9
respectively. Income and social prestige, as well as lower level of stress and emergency calls  with mean 3.61±1.0 and 2.48±1.4 were less important factors in choosing a specialty. Being in elective  non emergency situation and more relax atmosphere  was significantly
higher in women compare to  men (2.65 vs. 2.23 p>0.02).
Comparison of influential factors in selection of a  specialty among different residents were significantly different (p<0.05).

Conclusion: Considering first hand factors influencing their choice
such as the ability to better   helping people  compared to less important
factors such as social, economic and welfare indicates that most residents choosing their own interests and needs of the community.
Knowing these  factors will guide  residency program directors in  designing appropriate strategies  for educational and health care 
services.

Keywords: Factor affecting, Specialty choices, Medical residency, Ahvaz