Introduction: Job satisfaction plays a pivotal role in the performance of university faculty members. Identification of the factors influencing job satisfaction can be useful in advancing the educational and research objectives of the university. The aim of the present study was to analyze the factors influencing job satisfaction among the faculty members of Guilan University of medical sciences. Methods: This study was a descriptive cross-sectional research that was conducted in 2012. The statistical population of the research included 139 faculty members at faculties of Guilan University of Medical Sciences selected using stratified random sampling. The instrument of data collection was a questionnaire consisting of two sections; the first section contained 10 questions about demographic information and the second section comprised of 19 questions which was designed based on Herzberg's two-factor theory. The questionnaire was scored according to 5-point Likert scale. Data were analyzed by SPSS 18 software and descriptive statistics indices of frequency, mean, standard deviation and Pearson correlation coefficient reported.Results: 66.2% of the faculty members were male, 62.6% were clinical faculty members and 37.4% basic sciences faculty members. The most important factors affecting the faculty members’ job satisfaction were job security (4.14±0.96), friendly relationship with colleagues (4.01±0.81), and technology and technical knowledge (3.99±0.87). The most important motivational factors influencing job satisfaction were interest in job (4.24+0.71), achievement (3.99±0.87) and equal opportunities for career promotion (3.95±0.99).Conclusion: stability and job satisfaction, creating friendly working environment, proper environmental conditions, professor’s welfare and providing spiritual and material incentives are factors that influence the professor’s job satisfaction.