PurposeBeing innovative is important for non-profit sport organizations in order to meet the ever-changing and increasing societal needs. Understanding why and to what extent organizational innovativeness differs between non-profit sport organizations is, therefore, important to assess and increase their chances of survival. The purpose of this study is to compare the structural characteristics and attitudes of innovation attributes between three groups of sport federations (SFs).Design/methodology/approachAn online self-assessment survey was sent to all recognized regional Belgian SFs (N = 156). Simultaneously, an observational desk research (i.e. media analysis) was carried out. Results from both data collection methods were combined to develop a composite organizational innovativeness-index, based on which the federations were then clustered in three distinct adopter groups.FindingsComparative statistics show that structural background characteristics generally are poor indicators for adopter categorization. In contrast, the attitudes about compatibility (i.e. the consistency of innovations with existing values) and complexity (i.e. the extent to which innovations are difficult to apprehend) seem the most important distinctive determinants for the different groups of SFs.Originality/valueThe study's contribution is twofold. First, it offers a methodological contribution with the development of an index, which enables the categorization of non-profit sport organizations according to their organizational innovativeness; thus, it provides a critical counter-argument to the importance of organizational structural background characteristics from previous studies. Second, the study's results may support non-profit sport organizations in improving their innovativeness, for instance by improving the perception of compatibility with innovation or by guiding policymakers in creating a more supportive environment for these organizations to do so.