The literature has highlighted that relationship learning constitutes a value creation pathway in business and non-profit collaborations. However, this process has not been studied in detail. The main objective of this study was to carry out an in-depth analysis of relationship learning by examining the main factors that favor its development. For this, a research model was developed based on the relevant literature in the field of Relationship Marketing and Inter-Organizational Learning. The hypotheses were tested with data collected from 102 Spanish firms in collaboration relationships with non-profit organizations. The results reveal the importance of four relational variables in the direct and indirect explanation of relationship learning-values shared by the partners, trust, commitment, and cooperation. First, shared values form a key antecedent of trust and commitment, these in turn are fundamental precursors of the partners' cooperation, and commitment and cooperation showed themselves to be the main determinants of relationship learning between firms and non-profit organizations. The proposed model could enrich the relevant literature and provide better understanding of the relational aspects that businesses and non-profit organizations should work on if they wish to improve their level of relationship learning.