During complex decisions processes, such as a direct investment in Brazil, the risk aversion of a decision maker influences if and to which extent a company invests directly in Brazil. Furthermore, the special economic situation of SMEs determines the degree of risk aversion of the decision makers. In the current state of scientific discussion, no model for risk aversion exists. Therefore it is not possible to explain scientifically the risk-averse decision-making behavior and the influence of the economic situation of decision makers to complex investment decisions. To answer the thesis, a model of risk aversion with the variables risk expectation, experience, information, intuition, risk preferences and risk perception is developed. This doctoral thesis also investigated the relationship between the variables. The variables of the model of risk aversion are verified with the example of the risk aversion decision-making behavior of decision makers in SMEs at a Brazilian direct investment.