Purpose: This study was to examine the effects of Dan Jeon Breathing on physical endurance, cognitive function, and depression in middle-aged women. Methods: This study employed a quasi-experimental with a nonequivalent control group pre-post test design. Participants were 59 middle-aged women and randomly assigned to the experimental or control group. Dan Jeon Breathing was carried out for 40 minutes per day, 3 times per week for 12 weeks between March 1 and July 31, 2010. Data were analyzed by Mann-Whitney U test and Wilcoxon signed ranked test for paired data. Results: After Dan Jeon Breathing intervention, the scores of physical endurance and depression of the experimental group were significantly higher than those of the control group. However, the scores of cognitive function between two groups were not significantly different. Conclusion: The Dan Jeon Breathing can be utilized as a nursing intervention for physical endurance and depression in middle-aged women. Also, a revised model of Dan Jeon Breathing is needed to be examined for cognitive function.