This study recorded the diversity of fish caught in and around the Cabo Orange National Park in northern Brazil in 2008, and estimated the fishing effort and CPUE of the local artisanal fleet. Two fishery zones – the Oiapoque River and a coastal zone – were identified. Monitoring of catches recorded 34 fish species. A PCA of the catches of the seven principal species revealed marked loadings. The first factor indicated a positive association among the monthly landings of Plagioscion sp., Cynoscion virescens, Sciades proops, Notarius spp., Cynoscion acoupa and Centropomus ensife­rus. The Spearman correlation between the scores for the first PCA component and river discharge revealed a significant negative association (rho = -0.61; p < 0.05). Cynoscion virescens, Plagioscion squamosissimus and P. aureatus were the target species. Profits per trip varied from U{\$}500 to U{\$}1850. It is recommended that immediate action be taken to guarantee fishery operations within the national park and surrounding areas. In this context, a Marine Extractive Reserve (MER) would allow for the sustainable use of resources and may be a more feasible approach to the situation in the Cabo Orange National Park. This type of reserve would provide coastal communities with the legal framework necessary for the co-management of the reserve.