Putting a contract in real business situation requires trust and faith between parties involved. It is therefore important, to understand the principle of a rightful thinking legal mind-set or trustworthiness, when it comes to contract signing. Having faith in contracts is one of the principles that facilitates its implementation. In this paper, the author examines two legal concepts that is the rightful legal mind-set towards contracts and contract implementation. The research is basically a review one, which analyses the varying online data and documents regarding a rightful thinking legal mind-set in relation to the signing of contracts between parties and the implementation of such contracts from an Indonesian perspective. It has been established that an understanding of a legal mind regarding contract signing varies from individual to individual and also it varies from company to company depending on the form of collaboration. However, there is one thing noted, that is all contracts have one characteristic, which is faith or trust in contracts signed. This means having rightful thinking legal mind-set is a binding working basis for the smooth execution and or implementation of contract between two parties and or more entities.