‘Public interest’ (synonymous here with ‘common good’ and ‘public good’) is a central concept in public administration. In an important, basic sense, we evaluate the effectiveness of governments in terms of whether their policies are detrimental to, or benefit, public interest. However there are problems operationalizing public interest: it seems a concept that is simultaneously indispensable yet vague. While difficulties operationalizing public interest are widely understood, a further problem is insufficiently acknowledged. This is that many features underpinning public interest (a tradition of citizenship, stable government, a rule of law, basic infrastructures) are taken for granted in established democracies. However, in other contexts we cannot assume these. Examining what public interest means in developing countries can be useful to identify these taken for granted assumptions, and to re-examine this ubiquitous and enduring concept. We do this through a case study of land rights reform in post conflict Nicaragua.