As with all relationships, it is commonly agreed on that partners in business must have a high degree of commitment towards their relationship. If commitment is lacking, the relationship will soon come to an end. Affective commitment, that is commitment based on attraction between partners, is to be preferred over calculative commitment. The latter form of commitment is based on constant weighing of the benefits of a relationship with a partner against the costs of that relationship. Relationships based solely on calculative commitment are also most likely not to last for an extended time. This paper identifies theoretical antecedents and consequences of commitment in relationships in a services context. The results of an empirical study reveal that affective commitment is related to trust in the partner’s honesty and benevolence, quality of the outcome of the service process, and customer satisfaction with the service being delivered. The quality of the service process has an indirect effect on affective commitment, as it is related to satisfaction. Furthermore, it is shown that affectively committed customers have a much stronger intention to stay in a relationship with a service provider than calculatively committed customers.