This manual on sampling methodologies for the development of socio-economic indicators was initiated by the Sub-Committee on Economic and Social Sciences (SCESS) of the General Fisheries Commission for the Mediterranean Scientific Advisory Committee. It was prepared jointly by the Istituto Ricerche Economiche per la Pesca e IAcquacoltura (IREPA) and the Gabinete de Economía del Mar (GEM) within the framework of the ad hoc Working Group on Socio-Economic Indicators of SCESS. The manual is aimed at all decision-makers who may need to collect data to build socio-economic indicators. At an international level, it can be used to facilitate and simplify reporting under international conventions and agreements on matters relating to the sustainable development of the worlds fisheries. Regional fisheries bodies and stakeholders involved in fisheries decision-making, such as the fishing industry, other user groups, certification bodies, local communities and non-governmental organizations, may also draw upon this manual to assist in meeting societal goals for fisheries. The methodologies can be applied to fisheries at many different levels, from individual fisheries and coastal management units to a global level. The manual aims to encourage consistent use of statistical methods in data collection. Governments may also wish to adapt the manual to the specific requirements of their national fisheries.