Individual structure of values explains many behaviours that people consciously undertake when setting goals for themselves, both in personal and social dimensions. Altruistic behaviours may be influenced, for example, by personal concerns for the well-being and interests of others that fit into a broader framework of values. We use an online experiment to explore how donors (pure altruists, warm-glow givers and impure altruists) differ in their structure of values, and whether their prosocial behaviours are guided by specific sets of values and motivations. We find that donors give great importance to the relationship with others, and they identify themselves with the norms and attitude of a community, responding to the values of tradition, conformity, benevolence and universalism. On the contrary, non-donors do not seem to have this kind of values reference and, therefore, are not inclined to make a donation. Furthermore, we find that impure altruists wish to achieve self-enhancement objectives through altruistic behaviour, as pure warm-glow givers do, but, at the same time, they make a donation because it represents a genuine altruistic act, similarly to pure altruists. JEL: H41, C90, C91