The study of Argopecten purpuratus reproduction, post-larval settlement, stock size, and population size structure and shell growth was undertaken in the 2000s in the Rinconada marine reserve (Chile) to evaluate the effectiveness of scallop recruitment and self-sustainability.ăă* The results highlight strong seasonal and inter-annual variations of environmental conditions and scallop gonadosomatic index, spat collection, benthic distribution, total abundance and population size structure. The Von Bertalanffy growth parameters were L∞ = 120.12 mm and K = 0.9681; commercial size would be reached in about 17.2 months in the bay. Substrate availability, meteorological conditions, hydrodynamics and illegal harvesting explain spatial and temporal variations in scallop distribution and abundance. Recruitment strength depends on one main cohort from year to year. While recruitment made up 81% and 94% of total abundances in May 2002 and May 2003, respectively, there were no overall density-dependent relationships between stock size and recruitment. Spawning asynchrony in the bay supports the hypothesis that multiple gamete releases form part of a reproductive strategy in response to environmental variability. The massive disappearance of large-sized scallops during the study periods was direct evidence of overfishing owing to clandestine harvesting within the marine reserve. The failure of current legislation, strategies and policies for scallop conservation requires new regulations to restore scallop stock size, maintain its reproductive performance and limit illegal harvesting in the Rinconada. A scenario allowing harvesting regulated by stock-dependent fishing quotas would more efficiently ensure stock recovery and self-sustainability. The modalities of this new policy are discussed.