Aged workers were mostly questioned in terms of their work efficiency. However, as time changed and the structure of human resource in the organization also changed, older people became important part of all human resources in the organization. The study, hence, aimed 1) to study the level of work efficiency of aged workers; and 2) to study factors affecting work efficiency of aged workers. The study applied quantitative method using questionnaire as a data collection tool, collecting data from aged governmental officers in Nong Khai province, Thailand. There were 402 completed questionnaires which were taken for analysis. The finding presented that aged workers performed very high level of work efficiency using frequency, mean, and standard deviation techniques to analyze. To find the factors affecting work efficiency, the research applied multiple regression analysis. The finding presented that recognition and respect, fair evaluation, job design, and compensation were factors affecting work efficiency of aged governmental officers.