Deposit mobilization is the primary requirement for banking business to secure their existence. The objective of this study was to investigate the determinants of deposit mobilization for selected private commercial banks in Ethiopia. For the purpose of this study, five private commercial banks were selected based on their year of establishment and current performance. To achieve this study, tenyear data from 2012 to 2021 was collected and encoded in to EViews 12 and SPSS accordingly. In order to conduct this study, the researcher used eight independent variables namely Branch expansion, loan to deposit ratio, ATM availability, capital adequacy ratio, bank profitability growth, deposit interest rate, inflation rate and gross domestic gross (GDP). While conducting this research, the researcher employed quantitative research approach and explanatory research design. The researcher used a purposive sampling technique. Pooled OLS model was used for data analysis. profitability growth and ATM availability had a statically significant positive effect on deposit mobilization at 5% significant level. Whereas capital adequacy ratio had a statically significant negative effect on deposit mobilization at 5% significant level. Branch expansion, Loan to deposit ratio, and deposit interest rate had insignificant positively effect on deposit mobilization. However, GDP and inflation had insignificant negative effect on deposit mobilization. Finally, the researcher recommended that private commercial banks included in the study should expand their ATM availability around the rural areas of the country, specifically in small town areas of the country as far as the infrastructure is available. Furthermore, the researcher also recommended these private commercial banks to minimize their capital adequacy ratio by increasing loan and advance and should lend their excess capital as much as possible to attract additional customer and deposit.