The fashion industry continues to grow exponentially, along with marketers’ use of false and misleading claims about “sustainability” and other environmental attributes of fashion garments. This Article explores recent instances of greenwashing in the industry and other countries’ efforts to address the issue, and proposes specific ways that the Federal Trade Commission (FTC) should improve its guidelines for environmental marketing claims and expand enforcement. It provides an overview of the FTC’s authority to regulate under §5 of the FTC Act and an analysis of recent enforcement actions, and demonstrates how the agency’s current “Green Guides,” last revised in 2012, inadequately address greenwashing in fashion today. The FTC is currently in the process of regulatory review for the Green Guides, and the Article incorporates and responds to comments submitted during the public process.