Purpose: The purpose of this study was to determine the effects of the BeHaS exercise program on balance and walking ability in middle-aged women with knee osteoarthritis. Method: Participants were 36 patients (experimental group: 18, control group: 18) with knee osteoarthritis. Women with knee osteoarthritis in the experimental group participated in the BeHaS exercise program for 65 to 90 minutes per session twice a week for 12 weeks. Data were collected by a structured interview and measurement tool from September 1, 2005 to March 30, 2006. Descriptive statistics, such as frequency, percentages, means, SD and t-test, Chi square test were used with the SPSS Win 12.0 to analyze the data. Results: There was a significant difference between the two groups for dynamic balance, but differences in balance and walking ability were only partially supported. Conclusion: These findings indicate that the BeHaS exercise program could be a good nursing intervention for health maintenance and promotion of patients with knee osteoarthritis. Further research is needed in order to confirm these findings in elderly people with osteoarthritis.