Purpose This study aims to analyze the performance efficiency of private commercial banks in Iran as an Islamic economy. Design/methodology/approach A meticulously chosen sample comprising 15 private banks from 2020 to 2023 has been examined. This study uses data envelopment analysis (DEA) models, specifically the Constant Returns to Scale (CCR) with input orientation and the Variable Returns to Scale (BCC) with input orientation, to scrutinize performance efficiency relative to the banking sector’s average efficiency ratio. Findings The findings indicate that the performance of decision making units is superior in BCC models when determined with CCR models. The CCR-I analysis spanning 2020–2023 reveals that only two banks consistently demonstrated full efficiency performance, attaining a 100% efficiency score across all years. The observed fluctuations in banks’ efficiency performance are attributed to disparities between the growth or reduction in inputs and the corresponding augmentation or diminution in outputs. Research limitations/implications This paper has some limitations. First, selecting inputs and outputs for the DEA models is crucial, as this study’s results are sensitive to these choices. Second, this research focused exclusively on the efficiency of private banks and did not assess the efficiency of governmental banks. Practical implications The insights from this study can be valuable for bank managers in evaluating performance, regulators in maintaining financial stability and investors and market analysts in enhancing their investment strategies through bank performance analysis. Originality/value To the best of the authors’ knowledge, this study is the first to propose a framework for evaluating and forecasting commercial bank performance in an Islamic background. This model for prediction performance would be helpful for future research on the banking sector. In addition to improving Islamic banking literature, this research contributes to the literature regarding the analysis methods usually used.