To meet the challenges of producing more while lowering impacts on ecosystems, new fish-farming systems have to be designed. The first step before any changes in farming systems is to make a diagnosis on environmental impacts, economic viability and social aspects of the activity. The assessment step has to be as complete as possible, adapted to the system and scientifically robust, but also convenient for the user. To fulfil this complex combination, we designed an operational tool for fish farm systems assessment based on LCA conceptual framework and Emergy accounting: PISC’n’TOOL. This tool was created in the PISCEnLit project (Ecologically Intensive PISciculture project) funded by the French National Research Agency. PISC’n’TOOL aims to analyse environmental farm scale impacts of a fish farm according to LCA attributional approach, to determine the contribution of the farm’s components and environmental intervention to its impacts and also to analyse farm’s performances (zootechnical, economical, and social). The targeted users are researchers and agricultural advisors for fish farming in France, Indonesia and Brazil. PISC’n’TOOL applies a cradle to farm gate analysis; the farming system evaluated focuses on the fish farms and its main inputs (Figure 1). For fish farms associated to livestock (i.e. integrated pig -fish farming system), the terrestrial production are outside of the system boundaries, meaning manure/slurry used for fish production is considered as an input with specific allocation rules. Temporal coverage of PISC’n’TOOL is a period of 1 year or one production cycle in order to be adapted to the evaluated system. According to the multiple functions of a farm, PISC’n’TOOL defines 5 functional units: one tonne of fish produced, one m3 of water used, one on-farm hectare, one human labour unit, and 1000 $ of farm income, calculation depending on specific user’s data or incremented data base. The farm’s environmental inventory is based on tables of energy carriers, infrastructures, equipments, vehicles, chemicals and veterinary products, water consumption, feeds (up to 10 different feeds with 15 ingredients are allowed) and fry/fingerlings. These data stem from previous aquaculture LCA studies or new data collected during PISCEnLIT project. Farm emissions (N, P, solids emissions) are calculated using mass balance modelling [1]. Emission and consumption data are aggregated into midpoint indicators (included also Net Primary Production Use) according to CML 2 baseline 2001 (version 2.04) method and endpoint indicators (human health, Ecosystem and resources) according to Recipe endpoint H Eur H/A method. PISC’n’TOOL allows also to provide Emergy indicators (based on LCA data), but also zootechnical, economic efficiency level and social indicators (Figure 2). Results are systematically given in tables for each functional unit or in graphical form. The resultants ensure an easy comparison between different running scenarios for one farm or for different systems as well. Despite a large interne database, this tool requires additional data from the users to perform the LCA. PISC’n’TOOL is a practical tool for the multidimensional evaluation of farming system. The tool allows the identification of the environmental, economical and social hotspots of fish farm, and thus can help to define improved strategies and scenarios for farm evolution.