RBV posits tangible firmâ€™s resources are vital for superior business performance, as main source of competitive advantage. Private commercial banks in Ethiopia are facing stiff competition necessitating the design of competitive strategies to guarantee their performance. They have to know how and to what extent their internal resources affect their performance and then build competitive strategies to acquire these resources. This study aimed at examining the effect of bank specific tangible resources as sources of competitive advantage on the performances of private commercial banks in Ethiopia. Both explanatory and descriptive research designs were employed. While population of the study was 16 private commercial banks, purposive sampling technique was adopted to reach at 6 target banks, after selecting two senior banks from each three categories. 2009/10 to 2016/17 Panel data of target banks was collected and multivariate regression model with diagnostic tests were applied using STATA software. The study found bank size, total capital and total investment & expense were positively and significantly affected performances, while number of branch negatively and significantly affected performance. Bank size, total capital and total investment & expense used as sources of competitive advantage by the larger private banks while number of branch was not. The larger banks were mainly beneficiaries while the medium banks were competent relative to the smaller. We recommend medium banks to focus on internal growth and small banks on external growth either through mergers or acquisitions to gain competitive advantage. Theses private banks should have to revisit their aggressive branch expansion to moderate and multi channel distribution.