Purpose: The aim of this article is to illustrate the assessment procedure concerning the effectiveness of the inter-organisational cooperation in terms of practice represented by the creative sector companies under consideration.

Design/methodology/approach: The accomplishment of the research objective was based on the hypothesis that the effectiveness of the inter-organisational cooperation between companies in the creative sector constitutes an important determinant of strengthening the competitive advantage thereof. In order to assess the effectiveness of the inter-organisational cooperation, a categorisation method has been used, which belongs to the mathematical methods of multicriteria benchmarking.

Findings: The effectiveness of the inter-organisational cooperation between companies in the creative sector is an important determinant of improving their competitive advantage.

Originality/value: The paper describes the effectiveness of the inter-organisational cooperation between companies in the creative sector. We identify increasing and lowering factors of the effectiveness, describe the benefits model of the inter-organisational cooperation, and present the matrix of relations between the level of cooperation effectiveness and the level of competitive advantage. The article can be used by managers of the creative sector.