The purpose of this study was to measure the effects of trust, knowledge, optimism, risk and benefits on consumer attitudes toward genetically modified foods. A total of 326 questionnaires were completed. Moderated regression analysis was used to measure the relationships among the variables. The analysis results for the data indicated a good model fit in Model 2 rather than Model 1, in which the direct effects of trust, optimism and benefits had statistically significant direct effects on the respondents' attitudes toward genetically modified foods, while the direct effects of knowledge and risk were not statistically significant. As expected, the interaction term of risk and benefit had a significant effect on consumer attitude. Moreover, the effect of risk on consumer's attitude toward genetically modified foods was statistically significant at all levels of benefit, except at the lower benefit level. Finally, the results of this study indicated that genetically modified food developers and marketers should attach importance to the interaction effect of benefits to understand the elements of market demand and customer loyalty.