Electronic decision-support tools are now an essential component of government strategies to battle non-native species, with taxon-specific, paper-based risk analysis schemes often being replaced by taxon-generic tools. This study reports on the development of a decision-support tool for aquatic species, the Aquatic Species Invasiveness Screening Kit (AS-ISK), which replaces five taxon-specific toolkits for amphibians, freshwater and marine fish and invertebrates (FISK, MFISK, FI-ISK, MI-ISK, Amph-ISK). Adapted from Pheloung et al.'s Weed Risk Assessment (WRA), the "-ISK" toolkits were also "self-automated workbooks" in Excel (R) VisualBasic (R) architecture of the 'WRA. In creating AS-ISK, we incorporated the conceptual approach (questions and guidance) of the generic risk screening module of the European Non-native Species in Aquaculture Risk Analysis Scheme (ENSARS) into a single "turnkey application" that was based on the Excel (R) VisualBasic (R) architecture used by the WRA and its "-ISK" derivatives. Applicable to virtually all climatic zones and all aquatic plants and animals regardless of ecosystem (marine, fresh, brackish water), AS-ISK comprises 49 basic questions on the taxon's biogeographical and historical traits and its biological and ecological interactions. In compliance with the "minimum requirements" for use with the new EU Regulation on invasive alien species of EU concern, AS-ISK includes a preamble of background information on the species as well as questions on its potential socio-economic impacts and those on ecosystem services, and an additional section (six questions) for the assessor to predict how forecasted changes in climate are likely to influence the risks of introduction, establishment, dispersal and impact of a species. Following a concise but detailed description of AS-ISK, an example assessment of the Manila clam Ruditapes philippinarum is provided, with the French northern coastline as the risk assessment area, to demonstrate use of this decision-support tool. AS-ISK is available for free download at: http://www.cefas.co.uk/nns/tools/.