An influential body of literature in macro-management research (notably, organization theory and strategic management) associates pro-social motivation solely with firm-like organizations, suggesting that such motivation cannot thrive under more market-like arrangements. We question this argument on theoretical, as well as empirical, grounds. As to the latter, we discuss the specific case of a network of firms in Brazil, the Genolyptus network. We argue that this particular network manifests strong pro-social motivations. This implies that pro-social motivations may thrive beyond corporate boundaries, contradicting the above argument. More constructively, the case of the Genolyptus network points to the importance of intensive communication, rewards that are tied to joint outcomes, knowledge-based authority and consensual decision-making as support arrangements that can build and sustain pro-social motivations in non-firm governance structures.