In the early 2000s the Iranian government liberalized investment regulations and many foreign companies entered this high potential market where end-user consumers mainly comprise young people. Unfortunately, there are few studies of shopping behavior. This study compares Generation Y female and male consumer decision-making styles to offer guidelines to Iranian and overseas marketers. Sproles and Kendall's Consumer Styles Inventory (CSI) was adopted. The results show some differences between female and male decision-making styles, suggesting that gender affects shopping behavior. Identification of new traits suggests that CSI cannot be applied without considering socio-cultural factors.