There is little quantitative data on the cost effectiveness of environmental communication and education efforts. This study evaluates a public awareness campaign for the conservation of the Philippine crocodile in the northern Sierra Madre in terms of outputs, outreach, cognitive and affective outcomes, and impact through a counterfactual comparison. The campaign succeeded in raising awareness on and transforming attitudes toward in situ Philippine crocodile conservation: most people living in close proximity to crocodiles now know that the species is legally protected and support in situ conservation. As a result, crocodiles are no longer purposively killed. Substantial gains can be made in environmental conservation by investing more in communication, education, and public awareness campaigns, particularly in developing countries. Awareness on legislation and pride in the conservation of a rare and iconic species are strong incentives for poor, rural communities to support in situ wildlife conservation.