Background: In recent years, cloud computing has grown vastly. Cloud computing represents a new model for IT service delivery and it typically provides over-a-network, ondemand, self-service access, which is dynamically scalable and elastic, using pools of often virtualized resources. However, this new paradigm is facing diverse challenges from many fronts. Methods: We conducted a systematic literature review of potential challenges of cloud computing. Documents that described challenges of cloud computing were collected of routinely. We grouped identified challenges in taxonomy for a focused international dialogue on solutions. Results: Twenty-three potential challenges were identified and classified in three categories: policy and organizational, technical and legal. The first three categories are deeply rooted in well-known challenges of cloud computing. Conclusions: The simultaneous effect of multiple interacting challenges ranging from technical to intangible issues has greatly complicated advances in cloud computing adoption. A systematic framework of challenges of cloud computing will be essential to accelerate the use of this technology for working well in fact and in order to face with respect to mitigating IT-related cloud computing risks.