The Atlantic goliath grouper (Epinephelus itajara) is a critically endangered reef fish that has suffered from overfishing. In Brazil, the species has been under a fishing ban since 2002; however, there are no evidences of population recovery. In this context, data to help improve management programs are sorely needed. We assessed fisheries landings and interviewed key informants to investigate fishing, habitat use, and occurrence of goliath grouper in Abrolhos Bank, eastern Brazil. In mangroves, longline was the main fishing gear used to catch the species. Informants reported higher abundances of goliath grouper in red mangroves (Rizophora mangle) within shallow and complex channels. In marine reefs, the species was caught mainly through spearfishing. Goliath grouper occurrence was associated with coral and rocky reefs and was described as an aggregation site of up to 20 individuals. Informants also reported a decline in goliath grouper abundance across all habitats, primarily due to overfishing. Aggregation and nursery sites were mapped and described as essential for goliath grouper conservation. In Brazil, a scarcely enforced fishing moratorium alone is insufficient to guarantee the recovery of goliath grouper populations. Besides increasing the moratorium enforcement, we suggest implementing no-take zones, which encompass both nursery habitats and seasonal aggregation sites described in this study.