Decisions are an essential part of the life of every human. Every decision should be concerned with the goal, the resources available to achieve?the purpose, and the restrictions. The decision-making process is com-plicated, and the multi-dimensional environment for all decisions has to?be supported by a mathematical approach. Many scienti_c works are?based on the decision-making process. The _eld of this research is con-?cerned with Z-numbers proposed by Zadeh and its application in decision-?making. The Z-numbers' arithmetic is a crucial aspect of the article. The?proposed method combines Z-numbers and ranking of decisions by the?expert. The approach is based on the expert's knowledge expressed in?Z-number, where the reliability of the opinion, as a key factor, is consid-ered in the model of decision-making. The proposed method is illustrated?by a numerical example. In addition, case studies were carried out that?con_rm the usefulness of the technique in the decision-making process.