Background & Objective: Faculty members are one of the most important parts of "Input" in the "Educational system", so fine determination of effective factors on their "Job satisfaction" is critically important. This study was designed to evaluate effective factors on faculty members' job satisfaction in Mazandaran University of Medical sciences, 2006.Methods: In this descriptive cross sectional study, all faculty members (135 ones) of medical college who participated as the study samples completed a questionnaire (based on "Herzberg" theory) consisted demographic variables, 40 items in 11 domains for assessment of effective factors on job satisfaction according to 4 point Likert seal degree.Results: Among our sample, 106 faculty members participated in the study (87.5% response rate), majority of them were clinical specialists and sub specialists, and mostly were assistant professors (73.5%). The highest mean score (±SD) for effective domains on job satisfaction were as follow: salary 3.81(±0.61), condition of work environment 3.72(±0.75), job position 3.3(±0.81). The least important domains include: method of monitoring and supervising 1.91(±0.63), gratitude 2(±0.74), and communications 2.02(±0.85). Basic sciences faculties cared significantly more about salary; steady job, environment, career promotion and quality; while for assistant professors environment and responsibility were more significant.Conclusion: This study showed that external factors including salary and job environment were the most effective factor on job satisfaction of faculty members but factors related to organizational position of faculty members (communications and supervision) were less important. In Overall, this study indicated less importance of organizational and team spirit in faculty members and predominance of individual benefits, which should be modified by appropriate programs.