To compete with the flood of environmental messaging from corporations and industry groups, environmental advocacy groups must adopt the most effective communication strategies to connect with audiences and motivate their behaviors toward environmental issues. This study examines the framing of environmental messages by advocacy groups in contrast to messages by other organizations in 30 years of environmental advertising in National Geographic Magazine. It measures changes in the degree to which environmental actions were framed in terms of gain for the environment versus avoidance of ecological loss and in terms of impacting current generations versus future generation. In addition, the study examined behavioral frames of taking less (conservation) versus doing more (recycling, volunteering, etc.) in environmental advocacy groups' advertising to better understand the kinds of actions the organizations are promoting. The organizations' strategies to engage audience behavior were also measured through message focus on reader behavior versus organization behavior. Findings suggest that frames engaged by environmental advocacy organizations have remained fairly stable over time but may not represent the best practices for message creation. Copyright © 2011 John Wiley & Sons, Ltd.