Despite the large amount of extensive research on organizational demography, there has been a lack of conclusive evidence concerning the effects of organizational demography on performance outcomes. This study uses three different measures of performance-return on assets, economic productivity index, and price-cost margin-to investigate the relationships among organizational demography, employee turnover, and performance. Analysis of data from over 6,000 firms suggest that (1). Seniority configuration is unrelated to performance, but performance of the pyramidal organization is higher than diamond for age structure (2). the effects of age and seniority structure on performance do not seem to disappear even after turnover rate is introduced as a intervening variable, suggesting a robust direct effect of organizational demography on performance.