Through the marketing mix, there are many ways of promoting a business, such as a supermarket or a mini-mart. The core function of the marketing mix in the current commercial world is to satisfy the customers' expectations and needs. Therefore, organizations offer promises through the marketing mix using tools such as the product, price, promotion, and place to attract customers and fulfill their expectations. Companies and organizations tend to give affordable prices on top of the quality products they sell to their customers. This study, therefore, aims to examine the Impact of the 4Ps of marketing on students' purchase decisions in university mini-marts. Specifically, the study assesses the levels of product quality, price, promotion, place, and purchase decision amongst IIUM university students. In addition, correlation analysis is run to determine whether there is a relationship between product quality, price, promotion, and place with purchase decisions among university students who shop at university marts. The study utilizes the Theory of Planned Behaviour to explain the relationships between the variables. The quantitative research design and survey method with a questionnaire as the tool for data collection were used in this research. A total of 170 IIUM students participated in this study. The study findings reveal that students tend to consider price and place as essential tools in buying from the university mini-marts. In addition, the students also revealed that they do not consider product quality and promotion when deciding to purchase from the university mini-marts because of the factors highlighted in the study. The Theory of Planned Behaviour is also supported in this study.