Knowledge transfer (KT) is a trending topic phenomenon, widely studied due to its connection with the innovation processes in the firms and the competitiveness gained. Evidence of a close relationship between effective impact of KT processes, successful innovation, and higher business performance is already found out. Therefore, a corporate management guide instrument to rule the company through an optimal global KT tactic might become a noteworthy competitive improvement. Thus, the aim of this research is to depict an extensive model for optimal KT for those organizations who handle this resource as a strategic asset for competitiveness. We firstly analyze a set of theoretical KT models and taxonomies of recent formulation in order to develop a conceptual model which encompasses all factors enabling a successful result of KT. Then, we proceed with an empirical fieldwork, with the purpose of comparing and enhancing the discovery. The study is based on qualitative interviews with companies and institutions sited in the Basque Country and whose KT activities are frequent and heterogeneous. The model is conceived and illustrated as a compilation of dimensions of influences, highlighting the key performance factors for the firm. Finally, we display the findings of the study, bringing to light a direct link between KT impact and the extent of competitiveness of a company, and revealing a set of main success factors: suitable design and implementation of mechanisms to perform KT, effective cooperation between players, skilled management of the mix of knowledge, and propitious organisational culture.