<![CDATA[Abstract. The extreme fluctuation in profit margin income at Bank Muamalat during 20182025 underlies this research, with Net Profit Margin (NPM) changing by only 0.5% over eight years indicating the bank’s limited capacity to increase net profit. This condition is influenced by BOPO (Operating Expenses to Operating Income), which tends to rise up to 98% (indicating inefficient cost management), and NPF (Non-Performing Financing), which has declined sharply yet fluctuated. This study aims to analyze the effect of BOPO and NPF on NPM, both partially and simultaneously. This research employs a quantitative method with an associative approach, using secondary data from Bank Muamalat’s quarterly financial reports for 2018–2025. Data analysis includes descriptive statistics, classical assumption tests, multiple linear regression, the coefficient of determination (R²) test, the partial test (t-test), and the simultaneous test (F-test). The results show that BOPO has a negative and significant effect on NPM (regression coefficient -0.019408; probability 0.0011), and NPF also has a negative and significant effect on NPM (regression coefficient -0.017325; probability 0.0016). Simultaneously, BOPO and NPF significantly affect Bank Muamalat’s NPM. These findings confirm that operational efficiency and financing quality control are key factors in improving profitability, so the bank needs to maintain cost efficiency and minimize non-performing financing for optimal financial performance. Abstrak. Fluktuasi ekstrem pendapatan margin keuntungan Bank Muamalat periode 20182025 menjadi latar belakang penelitian ini, di mana Net Profit Margin (NPM) hanya berubah 0,5% dalam 8 tahun menunjukkan keterbatasan bank dalam memperbesar laba bersih. Kondisi ini dipengaruhi oleh BOPO (Biaya Operasional terhadap Pendapatan Operasional) yang cenderung meningkat hingga 98% (indikasi pengelolaan biaya belum efisien), dan NPF (Non Performing Financing) yang menurun tajam namun fluktuatif. Penelitian ini bertujuan menganalisis pengaruh BOPO dan NPF terhadap NPM, baik secara parsial maupun simultan. Penelitian ini menggunakan metode kuantitatif dengan pendekatan asosiatif, menggunakan data sekunder dari laporan keuangan triwulanan Bank Muamalat periode 2018–2025. Analisis data meliputi statistik deskriptif, uji asumsi klasik, regresi linear berganda, uji koefisien determinasi (R²), uji parsial (uji t), dan uji simultan (uji F). Hasil penelitian menunjukkan BOPO berpengaruh negatif dan signifikan terhadap NPM (koefisien regresi -0,019408; probabilitas 0,0011), begitu pula NPF (koefisien regresi -0,017325; probabilitas 0,0016). Secara simultan, BOPO dan NPF berpengaruh signifikan terhadap NPM Bank Muamalat. Temuan ini menegaskan bahwa efisiensi operasional dan pengendalian kualitas pembiayaan merupakan faktor kunci profitabilitas Bank Muamalat, sehingga bank perlu menjaga efisiensi biaya serta meminimalkan pembiayaan bermasalah demi kinerja keuangan yang optimal.]]>
