This study aims to examine the effect of capital structure and firm size on firm value with profitability as the intervening variable. This research was conducted on companies listed on the Jakarta Islamic Index 70 (JII 70) which are listed on the Indonesia Stock Exchange for the 2018-2020 period. This research is a research with quantitative method. The sample selection in this study used purposive sampling method and obtained 70 companies with 163 data samples. The source of the data for this research is the financial statements or annual reports published on the website www.idx.co.id. The data analysis technique used in this study is multiple linear regression with SPSS version 25. The results of this study indicate that capital structure has no effect on firm value, but firm size has a positive effect on firm value. While capital structure has a positive effect on profitability, firm size has no effect on profitability and profitability also has no effect on firm value. Meanwhile, profitability can mediate capital structure on firm value but cannot mediate firm size on firm value.