Globalization and the ubiquitous nature of the Internet facilitate e-commerce activities across nations. These activities demand a new conceptualization of online consumer behavior that transcends national boundaries and takes into consideration cross-cultural effects. To better understand what drives e-commerce across cultures, we apply a theory of planned behavior (TPB) perspective to capture behavioral intentions to transact online in two dissimilar countries – China and the United States. We argue that adoption of e-commerce depends primarily on consumer behavioral intentions to engage in product purchases. The model first draws upon the TPB to interrelate online transaction intentions with attitude, subjective norm, and perceived behavioral control. Second, given the uncertainty present in e-commerce, trust in a Web retailer is hypothesized as a salient belief that indirectly influences transaction intentions through attitude and perceived behavioral control. The paper’s major contribution is to incorporate Hofstede’s (2001) cultural dimensions - individualism/collectivism, power distance, and long-term orientation - in studying cross-cultural e-commerce adoption. We argue that these cultural differences influence the proposed e-commerce adoption model and moderate its key relationships. An empirical study was conducted to test the proposed cross-cultural model using data from consumers in China and the United States. The results render support for most of the proposed hypotheses, emphasizing the role of cultural differences on consumer e-commerce adoption. The paper discusses several insights from this exploratory study that contribute to the cross-cultural e-commerce literature. Finally, we discuss the study’s implications for theory and practice, concluding with several suggestions for future research on cultural aspects of e-commerce.