The reproductive biology of the white grunt Haemulon plumierii was studied from 360 individuals obtained from artisanal fisheries landings in the Abrolhos Bank, Brazil, between August 2010 and March 2012. The overall sex-ratio did not differ significantly from 1:1, although males predominated in larger size classes. β-Binomial modelling of historical sex-ratio data indicated that the catch rate of females has increased in recent years. Females reached maturity at a smaller total length (L ; 214 mm) than males (235 mm L ) and the L at which 50% of all individuals are mature (L ) was 220 mm, corresponding to 41·5% of the maximum recorded L . Variation in the gonado-somatic index and in the relative frequency of reproductive stages indicates that reproduction occurs year round, with increased activity during the austral spring and summer. Fecundity was not size dependent. The reproductive parameters provided here can support management measures focussed on seasonal closures during spawning peaks (September to November and February to March) and minimum sizes (>L ) for the capture of this important artisanal fisheries resource in Abrolhos, the region with the largest and most biodiverse coralline reefs in the South Atlantic Ocean.