The world has turned into a global village, thanks to a large number of communication media. The survival or success of a company now depends on the amount of information that is carefully collected with respect to the consumer habits that consumers are showing. Consumer behavior is a complex process that significantly influences purchasing decisions. Consumers on a daily basis make a number of decisions pertaining to the process of exchange and consumption of products and services. When consumers are making such decisions, they are influenced by cultural, social, personal and psychological factors. Consumers goes through a decision-making process that begins by recognizing a need and ends with buying and post-purchase behavior. This thesis is based on the research of consumer behavior when purchasing mobile devices. It is focused on recognizing and understanding consumer habits, and several factors are being explored that potentially affect the buyers decision when selecting mobile devices. The aim of the research was to determine how and when consumers change mobile devices. The results have shown that most users use the Samsung mobile device brand and according to respondents their prior experiences with the same brand has the greatest impact when making a purchase decision, as well as the most common reason for changing mobile phones was due to frustration with the current device. Since quality is a very important feature for users, manufacturers should focus on the production of high-quality mobile devices.