The purpose of this study was to examine the effect of capital structure,
firm size, and managerial ownership on firm performance with agency cost as
intervening variable. The population of this study is manufacturing company
listed on the Indonesian Stock Exchange in 2012-2016.The total sample is 21
companies. Sampling method using purposive sampling. In this studyusing
multiple regression analysis method.The results of this study indicate that the
capital structure has significant effect on agency cost, size has no has significant
effect on agency cost, and managerial ownership has significant effect on agency
cost. Capital structure has significant effect to firm performance, size has
significant effect to firm performance, managerial ownership has no significant
effect to firm performance. Meanwhile, agency cost can not mediate the
relationship between capital structure, size, and managerial ownership on firm
performance.