Poor mental health in doctors appears to be a global phenomenon, but there are limited data on changes in doctors' psychological symptoms over time in mainland China. Through a detailed meta-analysis of cross-sectional studies, our aim was to examine the prevalence of psychological symptoms in Chinese physicians as measured with the Symptom Checklist 90-R (SCL-90-R) and to explore the factors associated with doctors' mental health. A comprehensive search was performed in major English and Chinese databases. Thirty studies involving a total of 6,099 subjects were included in the meta-analysis. The pooled estimates of psychological symptoms including somatization, obsession-compulsion, interpersonal-sensitivity, depression, anxiety, hostility, phobic anxiety, and paranoid ideation among doctors were significantly higher than those in the general population. Only psychoticism was similar in prevalence to Chinese population norms. The prevalence increased with the study year but decreased with physicians' increasing age. Doctors from central and western China experienced more mental health symptoms than those from eastern China. Psychiatrists scored significantly less favorably than other doctors on most subscales of the SCL-90-R. Doctors' mental health may be associated with age discrepancy, quantitative workload, effort-reward ratio, doctor-patient relationships, professional identity, and individual traits. To minimize the risk of poor mental health in doctors, screening and professional intervention services should be provided at early career stages to raise physicians' awareness about the importance of maintaining psychological well-being and to reduce the prevalence of psychological symptoms.