Cloud computing is a new kind of computing model which allows users to effectively rent virtualized computing resources on pay as you go model. It offers many advantages over traditional models in IT industries and healthcare as well. However, there is lack of trust between CSUs and CSPs to prevent the extensive implementation of cloud technologies amongst industries. Different models are developed to overcome the uncertainty and complexity between CSP and CSU regarding suitability. Several researchers focused on resource optimization, scheduling and service dependability in cloud computing by using fuzzy logic. But, data storage and security using fuzzy logic have been ignored. In this paper, a trust evaluation model is proposed for cloud computing security using fuzzy theory. Authors evaluates how fuzzy logic increases efficiency in trust evaluation. To validate the effectiveness of proposed FTEM, authors presents a case study of healthcare organization. © 2020 IEEE.