This paper evaluates whether volunteering is imbued with altruistic or strategic reciprocity. Although scholars have intensively studied the motivations and social norms to volunteer, to date there is no agreement why human beings perform activities in which time is freely given up in order to benefit another person, group or organization. We argue that attitudes towards reciprocity and volunteering are related, but that this relationship becomes only visible if we refine the conceptual framework for both concepts. Using data from the Swiss Volunteering Survey 2009, the empirical results of our Bayesian multilevel models show the following: firstly, individuals exhibiting high levels of altruistic reciprocity are more likely to engage in informal volunteering; secondly, we find a negative relationship between altruist reciprocity and the individual likeliness to do voluntary work within non-solidary associations; thirdly, once individuals opted to engage in formal volunteering, we find that strategic reciprocity is clearly related to voluntary engagement in non-solidary associations. Overall, our conceptual foundation provides a more appropriate model to explain the formation of volunteering.