This study surveyed mobile users in the United States and Korea to determine the key differences between the two countries. Survey questions, developed in two languages, were presented in each country to explore the influences of informativeness, entertainment, interactivity, and availability on mobile user dimensions. The study design methods were based on the revision of a uses and gratifications approach, and a relational model of antecedents and consequences was tested with a structural equation modeling approach. Mobile Internet service uses and gratifications were analyzed cross-nationally in a comparative fashion focusing on the differences in the composition of motives in the two countries. Based on the results of this study, practical implications for marketing strategies in mobile service markets and theoretical implications for cross-country studies are recommended accordingly.