Growing threats and limited resources have always been the financial realities of biodiversity conservation. As the conservation sector has matured, however, the accountability of conservation investments has become an increasingly debated topic, with two key topics being driven to the forefront of the discourse: understanding how to manage the risks associated with our conservation investments and demonstrating that our investments are making a difference through evidence-based analyses. A better understanding of the uncertainties associated with conservation decisions is a central component of managing risks to investments that is often neglected. This focus issue presents both theoretical and applied approaches to quantifying and managing risks. Furthermore, transparent and replicable approaches to measuring impacts of conservation investments are noticeably absent in many conservation programs globally. This focus issue contains state of the art conservation program impact evaluations that both demonstrate how these methods can be used to measure outcomes as well as directing future investments. This focus issue thus brings together current thinking and case studies that can provide a valuable resource for directing future conservation investments. © 2014 IOP Publishing Ltd.