Changing human behavior and attitudes are key to conserving global biodiversity. Despite evidence from other disciplines that strategic messaging can influence behavior and attitudes, it remains unclear how to best design messages to benefit biodiversity. We conducted a systematic literature review to investigate the status of conservation messaging research, and to evaluate whether studies address essential elements of message design and theory from other disciplines. We show that academic interest in conservation messaging is growing rapidly. However, our results suggest that conservation scientists are not effectively drawing from the long-standing expertise of disciplines with well-established messaging techniques. Many studies do not draw on established behavior change theories or audience segmentation techniques. Given the urgent need to address the loss of biodiversity, we discuss how conservation messaging can draw on existing empirical and theoretical knowledge, with a focus on the application of established techniques used in messaging for pro-environmental behavior.