This paper aims to verify the impact of applying balanced scorecard on earnings quality controlled by Firm (Bank) size of banks listed on Palestine Exchange during the 2011–2019 period. To achieve this objective, a panel model relating to the dependent variable (Earnings quality) and independent variables (Balanced Scorecard components) with the control variable (Firm Size) was estimated, the researchers used financial reports and disclosures of the banks listed on the Palestine Stock Exchange as a tool to collect data, in addition to books, articles, and the previous studies. Descriptive quantitative research design was employed because of the use of quantitative data as proxies for both independent and dependent variables. Panel research strategy was applied for obtaining the cross sectional and longitudinal dimensions. The relationships between the study variables (Earnings quality, BSC components, and Firm Size) were estimated using Eviews version 7 (a statistical software). The results showed statistically significant negative effect of Customer perspective (CUS) on Earnings Quality (EQ); statistically significant positive effect of Internal Business Process perspective (IBP) on Earnings Quality (EQ); and statistically significant positive effect of Firm Size (FS) on Earnings Quality (EQ). In addition, the results showed no statistically significant effect of financial perspective (FP), Social perspective (SP), Learning and Growth perspective (LG), and on Earnings Quality (EQ). Furthermore, the results demonstrated that Earnings Quality of banks listed on Palestine Exchange was not high.