The retail sector in Brazil over the past few years, assumed major prominence in the business environment. Because of the accelerated consolidation featuring Brazilian retail activities, a lot of companies in this segment appear as the biggest in the country. From the expansion of these companies, the adoption of advanced information technology and management is necessary, contributing to the modernization and expansion of the Brazilian economy. Given this context, and seeking better alternatives in decision making process, many retailers are using geographical information. Among them, geomarketing, to assist in the expansion process and minimize the possibility of errors. Although many companies do not use the technology and their computational tools, those responsible for making decisions have a mental representation of the geographic distribution of its customers and markets. This information used in decision making process is directly linked to the geographical factor. This dissertation seeks, from a case study in a retailer of women s clothing; verify the application of Geomarketing and its use in expanding the business. By using qualitative research through case study, it was observed that this tool provides geographic information for analysis and decision making aimed at installing new outlets. The results show that the use of Geomarketing contributes and assists managers in decision making process for the location of new outlets process. The results also reveal difficulties in obtaining updated geographic data of the Brazilian territory. However, the introduction of analytical techniques using a combination of geography and marketing enables a gain for retailers to reduce the risk of error in choosing new points.