This article reviews major issues of mobile research in marketing, including the evolution of mobile phones as a research tool, characteristics of mobile research, and barriers to deployment of mobile research in marketing. It then describes the applications that either are currently in use or have immediate potential in mobile research, such as (1) testing advertising messages placed on the mobile web sites; (2) testing the use and dynamics of mobile search engines; (3) profiling mobile Web sites to understand demographics and other attributes of the sites; (4) assessing customer satisfaction with shopping or buying on mobile commerce sites or in brick-and-mortar environments; and (5) analyzing browsing behavior of mobile sites. Finally, the article explores the issues on integrating mobile research with online research and with mobile promotions.