This research is conducted to evaluate the determinants influencing the profitability of the food-processing firms in Vietnam. Data was collected from audited financial statements from the food-processing firms listed on the Vietnam Stock Exchange from 2012 to 2018 and panel regression model was used in the research (PLS). We selected the methods of testing the model's defects. The testing methods employed in this study were Pearson model, Hausman model, especially the relationship between FEM and REM; Modified Wald Test, Wooldridge test (for autocorrelation in panel data), and lastly Multicollinearity test based on VIF coefficient. The results indicate that Total-Debt-to Total-Equity and Long-term-Debt (TDTELT) had positive influence on profitability. However, Debt Ratio (DR), Short-term Debt Ratio (SDR), Long-term Debt Ratio (LDR) had negative impacts. Fixed Assets to Total Assets (FATA) and Firm size (SIZE) impact Return on Assets (ROA) without statistical significance.