This study investigated young millennials' risk perception, benefit perception, and purchase intention toward GM foods by testing the effects of source credibility and risk attitude. By comparing two samples collected in the U.S. ( N = 207) and China ( N = 242), we found that source credibility positively influenced benefit perceptions of GM foods among Chinese millennial consumers. Results also revealed risk attitude significantly influenced both American and Chinese millennial consumers' intention to purchase GM foods. Furthermore, a significant interaction effect between source credibility and risk attitude was found on Chinese millennial consumers' risk perception of GM foods.