There is a clear public interest benefit for lawyers to ensure access to the rule of law, especially on the part of the vulnerable. This article seeks to show that the seemingly simple relationship between the legal profession and the public interest is in fact more complicated than it looks. Pro bono may be viewed from two perspectives-that of the lawyer and that of the client. From the perspective of the lawyer, the important question is whether there is ethical motivation to engage in pro bono. If, however, the perspective of the client is paramount, then meeting the client's needs is the point of pro bono, irrespective of the lawyer's motivation. Our current approach to pro bono lacks coherence because we embrace both perspectives but seem unable to provide a satisfying account of the existing pro bono policies and programs under either view. Despite this complexity (or, perhaps, because of it), the public interest approach allows both lawyer and client perspectives to inform an understanding of pro bono publico. And, understood in a public interest paradigm, pro bono serves a vital and necessary role in the legal profession and the legal system.