ABSTRACT: Objective: Cross-sectional survey research was conducted to identify factors influencing job satisfaction among Thai health personnel who work at the North-Eastern Regional Health Promotion Center, Ministry of Public Health. Materials and methods: Participants were 178 health personnel. A two stage sampling technique was applied to select this group. Data were collected from 1 - 30 July, 2007 by self-administered questionnaire and were described/analyzed by frequency, percentage, mean, standard deviation, Pearson´s product moment correlation and stepwise multiple regression analysis. Results: The majority of those included (78.7%) had a moderate level of overall job happiness. Factors that significantly influenced job satisfaction (p<0.05) were life satisfaction, positive affect on the job, and reward and professional growth. These factors were responsible for 44.5% of job satisfaction among participants. Conclusion: Findings suggest that rewards should be given to outstanding personnel to motivate them for sustained good performance and to promote positive affect on the job. Promotion of professional growth through training opportunities to improve their career path should be strengthened to increase quality of work and job satisfaction.