Dietary potassium may neutralize acid load and reduce calcium loss from the bone, leading to beneficial effect on bone mineral density. In this nationwide Korean population study, dietary potassium intake was associated with improved bone mineral density in older men and postmenopausal women. Nutrition is a major modifiable factor that affects bone health. The accompanying anion in dietary potassium may act as an alkaline source by neutralizing the acid load and reducing calcium loss from the bone. We aimed to evaluate the association between dietary potassium intake and bone mineral density (BMD) in the Korean population. We analyzed a total of 3135 men aged >50 years and 4052 postmenopausal women from the Korean National Health and Nutrition Examination Survey (KNHANES). Lumbar spine, total hip, and femur neck BMD were measured using dual energy X-ray absorptiometry. The daily food intake was assessed using a food frequency questionnaire. When we divided the participants into tertiles based on the intake of potassium intake, the highest potassium intake tertile group showed a significantly higher total hip and femur neck BMD as compared to lower tertile groups (0.914 +/- 0.004, 0.928 +/- 0.003, 0.925 +/- 0.004 mg/day across the tertiles, P = .014 for total hip; 0.736 +/- 0.003, 0.748 +/- 0.003, 0.750 +/- 0.004 mg/day, P = .012 for femur neck). Postmenopausal women in the highest potassium intake tertile group showed significantly higher lumbar, total hip, and femur neck BMD as compared to those in lower potassium intake tertile groups (0.793 +/- 0.004, 0.793 +/- 0.003, 0.805 +/- 0.004 mg/day across the tertiles, P = .029 for lumbar spine; 0.766 +/- 0.003, 0.770 +/- 0.002, 0.780 +/- 0.003 mg/day, P = .002 for total hip; 0.615 +/- 0.003, 0.619 +/- 0.002, 0.628 +/- 0.003 mg/day, P = .002 for femur neck). Dietary potassium intake was positively associated with BMD in men aged >50 years and postmenopausal women, indicating the beneficial effects of dietary potassium intake on bone health.