Silver arawana Osteoglossum bicirrhosum are increasingly popular on the international aquarium fish market, but the routine killing of mouth brooding adults to collect juveniles for the trade may threaten wild populations. We describe the aquarium trade and fishery for silver arawana in the Peruvian Amazon. This is the first such report on the species for South America, and is based on field interviews with trade participants and fishermen, and on a review of government statistics. The regional trade is large, expanding and valuable (over 1 million juveniles worth USD 560,000 exported in 2001), of considerable economic importance to the rural poor, and in urgent need of research, monitoring and management. Outright bans on arawana fishing are likely to be ineffective and to destabilize an export fishery that provides significant part-time employment for the rural poor and substantial foreign earnings. Experimental studies are called for that compare the impacts on arawana yields of alternate fishing techniques, such as catch and release of brooding males, as a basis for developing more effective management schemes in Amazonia.