Cooperation is a strategy of an enterprise, seeking to retain its market share. The cooperation means the establishment of long-term relations of production between economically and legally independent enterprises. The measurement of the level of cooperation achieved plays an important part in this process because it helps to determine the effect of cooperation on the efficiency of commercial activities of an enterprise, as well as the extent of cooperation influence, the conditions required for effective cooperation of enterprises, etc. In the present investigation, the analysis of the cooperation influence on the competitiveness of an enterprise is made, based on the suggested formula for determining the level of the cooperation achieved by enterprises. The analysis performed shows that this influence is not strong, implying that the appropriate organisational forms of cooperation have not been found yet. Cooperation mainly affects the profitability of an enterprise. The analysis of cooperation in the area of production shows that cooperation in production, and the development of new technologies and new products is most important for achieving enterprise profitability. The number of partners also has a great influence on cooperation effectiveness.