© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. Crowdsourcing enables companies and individuals as well to tap into the versatile knowledge, creativity, and talent of a large population of crowd contributors. Yet, crowdsourcing can expose companies to a myriad of risks that can have drastic impact on the profitability and competitive position. This paper presents a Risk Breakdown Structure (RBS) of crowdsourcing projects that spans the entire project's lifecycle. The paper first reports on a lifecycle model that captures the main phases of a crowdsourcing project. It then identifies the risk factors associated with each phase of the crowdsourcing lifecycle and discusses the impact of these identified risk factors on the crowdsourcing company. The proposed RBS calls for the need to pay close attention to risk monitoring during each phase of the crowdsourcing lifecycle.