The open innovation model often neglects the frictions that external knowledge flows could encounter
when crossing organisational boundaries. This study recognises such barriers and investigates the
impact of these barriers on knowledge transfer effectiveness by using data on small new technologybased
firms (NTBFs) located in the emerging South African economy. The empirical results show that
the characteristics of inter-organisational knowledge exchange relationships (organisational and
technological similarity and contact frequency) do have an impact on the effectiveness of knowledge
transfer. The findings stress the relevance of a relational approach, as factors derived from it act as
barriers to effective knowledge transfer for small firms.