This article seeks to define the concept of tacit deceit within the crime of fraud. For this purpose, this study considers fraud as a crime against property, characterized by being a communication offense and a self-damage-crime. With that theoretical framework in mind, this research explains the concepts of active deceit and deceit by omission. It also argues that tacit deceit should be referred as a form of active deceit, characterized by the need to develop a deduction process on the issued message. The criterion used in this deduction process are the elements which define the economic relationship and without which the relationship would lose its meaning. Furthermore, tacit deceit should be interpreted as a false assertion, implicit and indirect, related to fraud-relevant facts. After outlining the definition of tacit deceit and the analysis of its most important cases, this study evaluates the posibility to recognize tacit deceit in Chile, applying the local fraud regulations contained in the Chilean Criminal Code.