Vibration analysis seldom has been used in detecting structural and mechanical changes in physiologic and pathologic bone conditions. We sought to correlate natural frequency of the radius measured by vibration analyses with bone mineral density measured by dual-energy xray absorptiometry and quantitative computed tomography (including cortical thickness). Sixty sedentary men between 50 and 70 years old were deemed osteopenic or healthy. A higher natural frequency of the dominant and nondominant radius was seen in the healthy men compared with the osteopenic men. Natural frequency was consistent with bone mineral density in dominant and nondominant radius in both groups. Moreover, there was a correlation between bone mineral density measured by dual-energy xray absorptiometry and natural frequency in the dominant and nondominant radius. Cortical thickness of the dominant and nondominant radius also correlated with natural frequency. We concluded natural frequency measured by vibration analysis is a precise method for the assessment of structural properties of bone and correlates with the bone mineral density of the radius.