Fishery is still key to livelihoods of over a million poor people in Sri Lanka, although the recent tsunami has destroyed nearly a third of the fishing fleet. This study focuses on a fishery in the Negombo lagoon on the west coast, which was not affected by the tsunami. In the lagoon, the main challenge is the well known fishery management issue of open access. One example of a long standing collective arrangement for successfully limiting open access is the “kattudel” or stake – net fishery association. The stake-net is a traditional fishing net used by small scale fishers to harvest shrimp as they migrate from the estuary back out to sea. This membership-based organization has been in existence for over 250 years and was codified in the government regulation in 1956. Members own a “pella” or share of the fishery, which is a written document recognized by the courts. While still poor, members of the society have, through their access rights to the fishery, been able to gain incomes higher than average incomes of the Negombo lagoon fishers. The night time nature of the fishery allows many members to have other jobs during the day. In addition, the society appears to have managed the output of prawns in a way that is equitable for its members with reduced social conflicts and without depleting the resource noticeably. This membership based association has been helped by specific characteristics of the prawn resource, by cultural and political factors through close affiliation with the Catholic church, and by the strong leadership. However the society is now facing challenges due to declining productivity of the fishery and other external threats to the lagoon. This has stimulated the society to work with other fishing groups in the Negombo lagoon to limit access to the wider lagoon as a whole. Success or failure of this major undertaking that attempts to replicate the society’s success within the Stake-net fishery across the many diverse fisheries of the lagoon may determine whether the stake-net fishery society can sustain the benefits of the fishery to its members in the future.