Introduction: The competitive condition of the world is such that the organizations make quality improvement, increase customers' satisfaction, reduce costs and increase productivity. Existence of such environment cause the variety technique and approaches such as total quality management, re-engineering, value engineering, lean production and Six Sigma. Six Sigma as the newest program of quality management helps organizations toward increasing customer's satisfaction and financial saving. The objective of this research was to shorten the stay of orthopedic patients who had to undergo a surgical treatment in Firoozgar teaching hospital, based on training DMAIC cycle to project team.

Methods: Present research is a cross sectional-longitudinal study. The time period of the project was estimated to be seven months. Length of stay data before training (three months) and after training (four months) collected by patient's dossiers and analyzed by Minitab software, using t-test.

Results: The mean of length of stay before training DMAIC in a sample of 200 patients was 7/915 days and after training was 6/375 days. Using the mean comparison indicated that there is a significant relationship between training DMAIC and the mean of length of stay (p-value<0/001).

Conclusion: For use of Six Sigma methodologies in quality improvement of hospital services, training is so important. Six Sigma training emphasis on tools learning and DMAIC process that it facilitates the implementation Six Sigma in organizations. ô°û 11 / یپ°û 43 / ی·}پَ 7831 Keywords: Six Sigma, DMAIC cycle, Training, Length of Stay