PURPOSE: The number of benign prostatic hyperplasia (BPH) subjects has been increasing worldwide, and many studies have been conducted to determine the treatment that can delay drug therapy or surgery. Subsequently, most of these studies involved physical activity (PA) and associated factors. Therefore, we aimed to determine factors associated with BPH prevalence based on a review of past and present studies and to investigate the effect of a healthy lifestyle as a protective factor of BPH occurrence. METHODS: We selected 582 subjects aged > or =40 years from an initial 779 subjects recruited from Gyeonggi, Yangpyeong, South Korea, during August 2009 to August 2011. Trained investigators surveyed International Prostate Symptom Score and demographic information, including PA and lifestyle questionnaire during face-to-face interviews; further, they performed digital rectal examination, rectal ultrasonography, and measured prostate-specific antigen levels. The statistical association between PA and BPH was analyzed by logistic regression analysis using multivariable regression models which use categorical variables by the Cochran-Mantel-Haenszel test and continuous variables by the general linear model. RESULTS: Seven statistically significant variables for PA were selected. Regular exercise, frequency of exercise, sedentary time, nonsedentary time, leisure time PA (metabolic equivalent, hr/wk) were not statistically associated with prostate volume but sedentary time (hr/day) was the only factor that showed a significant association in the multivariable model, including a linear effect relationship. Subjects with lower levels of sedentary time (4.5-7.0 hr/day) had a significantly lower risk of BPH (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.52-1.67) than those with a higher sedentary time (>7 hr/day) (OR, 1.72; 95% CI, 0.96-3.09) (P for trend=0.05). CONCLUSIONS: Our study showed that reducing sedentary time could have a protective effect and reduce the prevalence of BPH. Further prospective studies with a larger sample size are needed to assess the impact of reducing sedentary time on BPH risk.