Knowledge of the motivations of managers to practice Corporate Social Responsibility (CSR) is a critical issue for those who promote its adoption. The understanding of these reasons is complicated by the fact that there are different ways of defining this responsibility, raising the question of whether there is any relationship between reasons for adopting it and how to define it. To address this issue, a classification of these reasons was constructed and related to a classification of the different ways of defining CSR. A self-administered questionnaire was applied to a non-probability sample of Social Responsibility managers, which included indicators for both classifications. It was found that these managers present all types of motives, with proactive outweighing reactive motives and that there is a significant degree of correlation between the ways of defining CSR and the reasons for doing so. This suggests that managers present coherence in their objectives (motives) and means (practices of Social Responsibility.