Cloud computing provides an effective computing technology in the way IT services such as data storage, network, and application are supplied externally by companies without software and hardware, long implementations, and delayed maintenance to decrease operational expenditures. However, there is an inadequate amount of scholars studying the effects of cloud computing adoption among Turkish companies. In order to fill the gap, this study aims to exhibit the factors affecting cloud computing adoption in Turkish companies. Diffusion of innovation (DOI) theory was developed to understand the critical factors affecting cloud computing adoption, deriving three factors: perceived advantage, cost-saving, and compatibility. Confirmatory factor analysis was applied to assess data. The findings showed that compatibility directly affected cost-savings. Cost-savings directly affected perceived advantage, and perceived advantage directly affected cloud computing adoption. The variance of perceived advantage also explained 15.8% of the proposed model. By adopting DOI theory, this study will intend to contribute to businesses for increasing the awareness of companies' IT decision-makers about the perception of cloud computing adoption in the cloud computing decision making period in Turkey.