Aim To examine the job satisfaction of nurses who are caring for older adults in healthcare settings in Shanghai, and to explore the underlying factors in order to explain and predict nurses' job satisfaction. Background China has the largest elderly population in the world, and its population is aging rapidly. Studies on job satisfaction of nurses providing care for the elderly in China can help to identify problem areas and develop strategies for the improvement of nurses' working conditions. However, to date, this subject matter has not been thoroughly studied in the Chinese context. Previous studies in other countries show that many factors impact nurses' job satisfaction, with the practice environment being a critical factor. There is a serious nursing shortage in China, especially in the big cities such as Shanghai. Given the increasing care demand of the aging population, learning about the job satisfaction level among nurses who are caring for older adults can provide essential information to help attract and retain nurses in this specialty area. Methods A cross-sectional survey was conducted among 444 nurses in 22 elderly care institutions in Shanghai. The Chinese version of the Index of Work Satisfaction (IWS) and the Nursing Practice Environment Scale were instruments used. Inferential statistical tests used to analyze the data included Spearman correlation analysis, one-way analysis of variance, and hierarchical regression tests. Results The average overall IWS (part B) score was 135.21 +/- 19.34. Personality, job and organizational characteristics were found to be the most influential factors, and the practice environment was identified as having the strongest impact on job satisfaction (Beta = 0.494). Conclusion Job satisfaction level among nurses who are caring for older adults in Shanghai is moderate, but the data suggest that this could be greatly increased if the nursing practice environment was improved.