The main objective of this research is to determine the effect of financial literacy, trust, and payment security on purchasing decisions in the marketplace. The approach used is quantitative and uses the causal associative method. The study population was students of Surabaya State University Accounting Education and for sampling used saturated sampling technique, where all members of the population who have made purchases in the marketplace are used as samples. Data were collected through tests and questionnaires which were then tested using multiple linear regression analysis techniques. The results showed that each independent variable had a partial and significant effect on the dependent variable because the results t count> t table, and the significance value showed the results below 0.05. The variables of financial literacy, trust, and payment security also simultaneously and significantly influence purchasing decisions in the marketplace with the results of F count (43.344)> F table (2.680) and a significance value of 0.00 <0.05. The result of the coefficient of determination (R2) shows the number 0.512, which means that the influence of financial literacy, trust, and payment security variables is 51.2% and the remaining 48.8% is influenced by other factors.