While it is widely acknowledged that cloud computing has the potential to transform a large part of the IT industry, issues surrounding the adoption of cloud computing have received relatively little attention. What research has been conducted has tended to focus on technical issues and is based on a rather simplistic binary view of adoption – either the technology has been adopted or it has not. This study goes beyond a binary view of adoption and instead examines the more complex nature of cloud computing assimilation. It examines challenges to (i) acceptance - the extent to which an organisation’s members are committed to the adoption, (ii) routinisation - the extent to which the use of cloud becomes a normal activity, and (iii) infusion - the extent to which its use is extensive, integrated and emergent. Drawing on a field study of cloud assimilation across ten organisations, this study will contribute to the existing cloud technologies literature that does not address the complex and multi-faceted nature of adoption. Secondly, it will provide an insight into cloud computing adoption by focusing on the benefits and challenges associated with implementation in organisations.