Increasingly, when taking action on a company, it is essential to bear in mind the relationship between supplier and customer, which is a crucial element in determining a company’s presence in the market. In this area, human capital, knowledge and intellectual capital are also increasingly appreciated, especially in the long term. More and more companies understand that knowledge management is a step towards improving not only the selected process (in the case under study, in the area of cooperation with suppliers) but also the entire organization. The purpose of this article is to check whether in companies operating in Poland in the metal industry, the staff subconsciously uses elements of knowledge management - implementation of practices developed in the company, modification of existing procedures, sharing knowledge in the team, independent actions to improve the performance of work - which may be she had never heard. The research instrument that allowed to obtain the results was a questionnaire. The most important element of the review of the obtained results was the analysis of the importance of knowledge management factors and their impact on the formation of mutual relations between suppliers and partners of selected enterprises in the metal industry in the context of selected Toyota management principles. The adopted approach made it possible to identify differences in the responses of the respondents in both groups of enterprises, while providing a basis for further research on the directions of improving cooperation with suppliers using elements of knowledge management.