This study is aimed at investigating the factors affecting job satisfaction of employees working in health and medical institutions and organizations using the meta-analysis method. For this purpose, the quantitative meta-analysis method with a correlational approach based on the Glass and Smith (2008) executive meta-analysis model was used. The statistical population included all researches and studies related to job satisfaction in health and medical centers and institutions in the country. After collecting 1909 research documents and screening them through five stages, 77 research documents were selected as the sample size using purposive sampling in the form of 136 hypotheses. Data collection was carried out using the documentary method, relying on the recording of research texts and documents based on demographic checklists, and data analysis was carried out based on the overall effect size. The research findings showed that the average random effect size of factors affecting job satisfaction is 0.299 that is at a moderate level. Given that the estimated size is within the confidence limit, the effect of various organizational, cultural, social, economic, individual, etc. factors on job satisfaction was confirmed. Also, the moderation analysis showed that the effect size of factors affecting job satisfaction was higher for women than for men, higher for nurses than for other healthcare workers, and higher in the central and southern regions than for other regions. With the increase in the year of research, the intensity of the effect of various factors on the job satisfaction of employees in healthcare centers in the country decreases, and social factors (0.696), cognitive-metacognitive factors (0.595), and communication factor (0.428) had the greatest effect on job satisfaction.