In an increasingly complex and dynamic economic and business context, the study of the relationships that firms establish with their suppliers is a very important topic. Firms must use these relationships to ensure that the inputs they acquire are the most appropriate to achieve the desired product. But since not all firms, particularly SMEs, have personnel specifically trained to manage these relationships, or even to manage the firm itself, difficulties can sometimes arise in the management of the firm's supply function. The relationship marketing literature considers it beneficial to establish lasting relationships both with customers and with suppliers. It may be that people who are less well-educated academically are not aware of this situation. Thus, the current work aims to analyse the possible influence of the educational level of the purchasing/supply manager on the long-term orientation of firm-supplier relationships. Specifically, we use a sample of Spanish firms to analyse the moderating effect of this variable on the temporal orientation. Dividing the total sample into two subsamples – "better-educated" and "less well-educated" managers responsible for the supply function – we obtain some very interesting results and implications about the effects of trust, communication, cooperation, satisfaction and commitment on the temporal orientation of such relationships.