The purpose of this research is to investigate the influence of Capital Adequacy Ratio, Operating Income Operating Costs, Loan to Deposit Ratio and Bank Size to Non-Performing Loans in Commercial Banks in Indonesia. The sample used in this research consists of 38 commercial banks. The sampling method is non probability sampling with the sampling technique using purposive sampling. The analysis is performed by using the Panel Data regression analysis by the Random Effects Model in testing the hypothesis. The results show that Capital Adequacy Ratio, Operating Income Operating Costs, Loan to Deposit Ratio and Bank Size have a positive effect on Non-Performing Loans (NPL).Tujuan penelitian ini adalah untuk mengetahui pengaruh Capital Adequacy Ratio (CAR), Biaya Operasional Pendapatan Operasional (BOPO), Loan to Deposit Ratio (LDR) dan Ukuran Bank (SIZE) terhadap Non-Performing Loan (NPL) pada Bank Umum Konvensional di Indonesia. Sampel yang digunakan dalam penelitian ini terdiri dari 38 Bank Umum. Metode pengambilan sampel yang digunakan yaitu non probability sampling dengan teknik pengambilan sampel menggunakan purposive sampling. Analisis dilakukan dengan menggunakan Analisis Regresi Data Panel dengan Random Effect model dalam pengujian hipotesis. Hasil menunjukkan bahwa Capital Adequacy Ratio (CAR), Biaya Operasional Pendapatan Operasional (BOPO), Loan to Deposit Ratio (LDR) dan Ukuran Bank (SIZE) berpengaruh positif terhadap Non-Performing Loan (NPL).