Risk has been considered as one of very important topics in traditional consumer behavior theoretically and practically since its tendency of minimizing errors rather than maximizing utilization in addition to its intuitive appealing with very high explaining power. In addition to a traditional view of risk, importance of risk in online transactions such as Internet banking is due to technical instability in security of the Internet as well as temporal and spatial separation of transaction partners. Therefore, risk in online transactions should be analyzed by a very comprehensive way since it is very inherent in the Internet. The objective of this study is to suggest a research model for explaining the use of online transactions in some risk related variables including risk results, security result, perceived security, and social influence and show its validity by applying it to Internet banking users. In result, hypotheses suggested by our research model are shown to be valid ones.