Lobster fishing is the main source of income for the people from the Juan Fernandez Archipelago (population ca. 770), located more than 700 km off central Chile. An artisanal fishery has operated uninterruptedly for more than a century with few harvest controls (season, size, no egg-bearing females). Access to the resource has long been regulated by an informal but well structured traditional sea tenure system, which has effectively constrained the growth of fleet size. Nevertheless, and in spite of a lack of impending crises, assessments conducted over the last 40 years have recurrently diagnosed that effort is well above the optimum level. On that basis, generic "solutions" (quotas, marine protected areas, closures) have been prescribed with no attention to their possible impacts on the users and on traditional tenure arrangements. We discuss the merit of those diagnostics and prescriptions, and conclude that the disruption created by their eventual implementation would threaten the sustainability of the fishery. An analysis of the entire social-ecological system is needed before drastic solutions are prescribed. We investigate the factors that favor sustainability using Ostrom's framework for the analysis of social-ecological systems. Those factors have to do with the resource system (a productive stock with well defined boundaries and divisibility of fishing spots among users), governance (traditional tenure and simple operational rules), the users (few, strongly dependent on the resource, and sharing a detailed mental model of the resource system), and interactions (self-organization and partnerships). The resilience of the system was tested by the devastating tsunami that hit the islands in February 2010. This case study illustrates the need to attend to the interactions among resources, users and institutions in the search for effective solutions and to avoid disruptive management interventions. (C) 2013 Elsevier Ltd. All rights reserved.