Purpose: The purpose of this study was to identify the effects of a BeHaS exercise program on pain, health status, body weight in middle-aged women who have osteoarthritis in their knees. Method: The participants in this study were eighteen women whose mean age was 56.22years and who had osteoarthritis in the knees. The BeHaS exercise program consists of approximately one and half hour of exercise, two days per week, for twelve weeks. Data were gathered from September 2005 to December 2005 using a questionnaire and measuring VAS for pain, KWOMAC for health status, body weight for scale. Data were analyzed with the SPSS Win 11.0 using frequency and paired t-test for differences between pre-exercise and post-exercise. Results: The results of this study are as follows: Scores for pain on post test were statistically lower than pre test(t=4.202, p=0.001), health status was statistically improved after exercise program (t=3.479, p=0.002). But body weight did not change(t=-.774, p=0.222). Conclusion: From these results, it is concluded that the BeHaS exercise program can be effective in decreasing pain and increasing health status in middle-aged women with knee osteoarthritis.