The purpose of this research was to determine the optimal capital structure which could maximize profits and
corporate value. The used method was quantitative descriptive analysis. Moreover, the data used was secondary
data in the Jakarta Islamic Index (JII) from 2011 to 2015. The results of this research show that companies which
have optimal capital structure are in line with the trade-off theory models. The capital structure is optimal if the
debt levels are to a certain extent so that the corporate value will increase. However, if the debt limit passes the
certain degree, profit and corporate value will decrease. Meanwhile, pecking order theory in this research does
not conform and cannot be said to be optimal because of the low debt level describing the opposite result with the
theory as low profits.