Customer behavior has always been an interesting component of the purchasing process. As a scientific discipline, it appeared in the second half of the 20th century due to the change in the focus of the business concept from production to marketing. Various factors such as different reactions of consumers and their atypical behavior on the market contributed to the additional curiosity for understanding consumer behavior. The practice has shown that consumers are prone to certain behavior due to emotions and other factors and that they are not exclusively guided by rational decisions making. These findings became fertile ground for the development of the field of market research. The process of market research has progressed with the development of science and today it has taken a certain shape due to the progress of technology and science. Like any research, the process of market research begins with defining the problem and determining the goal of the research. Then follows the process of data collection and data processing to create a report. Report is used as a recipe for solving the problems that prompted the research process for a better understanding of the problem and its characteristics. The emphasis of the paper is on the understanding of observation methods in market research as a data collection method and its closer explanation of its verification. The process of implementing the observation method includes knowledge of the observed variables and their careful recording in the natural circumstances of the observed process and the behavior of the subject. The method of observation will be presented through the conducted research using an example of observing customers of a clothing store.