Purpose: The purpose of this study was to examine the effects of physical activity on glycemic control among Koreans with type 2 diabetes. Methods: A total of 215 patients with type 2 diabetes (82 male and 133 female) were recruited (mean age = $59.0{pm}9.7$ years). The amounts of physical activity was assessed using the physical activity scale for elderly (PASE). Fasting blood glucose (FBG), Hemoglobin A1c ($HbA_1c$), and 2 hours post-prandial glucose (2hrPG) were measured. Results: The highest PASE score was housework-related physical activity. However, the amounts of walking was significantly higher in good FBG level (Z = 1.39, p=.041) and the amounts of leisure-time physical activity was higher in good HbA1 and 2hrPG level than in the poor glycemic control group (Z = 2.29, p<.001; Z = 1.99, p=.001). A logistic regression analysis showed that patients with leisure-time physical activity in the top quartile more likely presented with good glycemic control in $HbA_1c$, OR=3.84 (95% Confidence Interval (CI) = 1.65~8.95) and in 2hrPG, OR=4.06 (95%CI = 1.77~9.27), compared to patients in the lowest quartile. Conclusion: Leisure-time physical activity is effective for controlling the glucose levels, especially $HbA_1c$ and 2hrPG among type 2 diabetic patients. It is suggested that health providers need to more focus on providing aggressive recommendations on physical activity considering physical activity patterns by individuals.