SUMMARY
Shopping centers are dynamic and changing systems that gather diverse offers of brands, products and services, becoming attractive environments for buyers, who are faced with the "buy or not buy" dilemma or, " buy now or buy later ". Since internal and external factors determine consumer’s behavior, the following questions arise: do people tend to be rational or impulsive in their purchases? Which factors determine a rational or an impulsive purchase? We studied the level of rationality/impulsivity as well as the most relevant factors that influence purchase decisions of groups of students from two different Chilean cities (Santiago and Punta Arenas). Our results reflect the influence that special deals have on students’ purchasing in shopping centers; the importance of product quality as an attribute of their purchase decision, and the satisfaction of their expectations as a determining factor after buying a product.