This research presents an investigation about the decision-making process regarding Make or Buy, trying to understand which variables most influence this decision to insource some activities, to outsource others, or to better estimate a percentage to combine both. The dependent variable on our research is the behavioral decision-making process, measuring the influence received by cost, quality, and monitoring. Trying to understand if differences between these independent variables influence how managers make their decision in the context of insource or outsource production. In order to test this model empirically, an experiment research was conducted, on the basis of eight different scenarios, which simulate a purchasing decision situation ranging the variables costs, quality, and monitoring of suppliers between High and Low, to understand the relationship of these constructs with the decision-making process of Brazilian managers. It was performed with a sample of 211 students from the Production Engineer course at Universidade do Rio dos Sinos (Unisinos). The data was analyzed using statistical technique ANOVA. The results demonstrate that managers consider cost variation to decide about how much to internalize and how much to outsource. They change their choices when quality is higher in their suppliers than inside the company. They also evaluate manager capability to control costs over their suppliers and on their process inside the company. However, they do not change their sourcing decision due to supplier’s monitoring variation, neither when quality monitoring is considered. This issue was already addressed in Hall’s study (2012) conducted in the United States. Thus, we decided to replicate his in Brazil in order to check if in a different environment, with other economic, politic, social, and regulatory situation, the manager will change their decisions. Nevertheless, after comparing both studies, we realize that the same hypothesis was supported in both studies, what means that even in another context the same variables are considered to base managers sourcing decision.