Abstract Growth, mortality and recruitment were determined for a loco (Concholepas concholepas) population from Huasco (Northern Chile) six weeks after suspension of a two years closed fishing season. The study was based on a shellmound sample of 2103 specimens that came from a processing plant. The von Bertalanffy growth parameters obtained (Loo = 152–160 mm, k = 0.38–0.52) indicate a faster growth and a smaller asymptotic size than reported in the literature. Recruitment seems to occurr during most of the year being strongest over a period of 4–6 months, probably during winter and spring. Total mortality was estimated as approx. 75% per year, about 10% lower than reported for loco populations of Central Chile previous to the closed fishing season.