Particularly among younger generations, the quick expansion of financial technology (Fintech) has profoundly altered personal financial management. This article investigates how Fintech influences savings behavior among young Vietnamese using a positive attitude as a mediator under the Unified Theory of Acceptance and Use Technology (UTAUT) paradigm. Living in major Vietnamese cities, ages 18 and 35 took a structured online survey to supply data. The applied model was partial least squares structural equation modeling (PLS-SEM). The most important direct effects on positive attitude are enabling conditions (β = 0.526, p < 0.001) and performance expectation (β = 0.202, p < 0.001), which subsequently encourage saving behavior (β = 0.532, etc.). Though it has little effect (β = 0.104, p = 0.011), social influence significantly affects a pleasant attitude. Emphasizing the important mediation role of positive attitude between technology adoption factors and financial behavior, the proposed model explains 54.7% of the variation in positive attitude and 28.3% in saving behavior. This study extends the UTAUT framework by incorporating psychological elements. The findings also provide policymakers and Fintech businesses striving to increase digital financial literacy and infrastructure meaningful analysis, inspiring more young people to pursue environmentally friendly financial practices.