The ICES Working Group for the Celtic Seas Ecoregion (WGCSE) met from 9th–18th May 2012 at ICES Headquarters in Copenhagen. There were 22 participants from six countries (Belgium, France, Ireland, Norway, the Russian Federation and the UK) present at the meeting and an additional six who contributed by correspondence. The WG was also attended by three members of the ICES secretariat (who assisted the WG with their advice drafting tasks) and by a European Commission observer. The meeting was chaired by Helen Dobby (UK) and Joël Vigneau (France). In total the WG provided assessments and draft advice for 37 demersal fish and Nephrops stocks across ICES Subareas VI and VII (with the distribution of megrim extending into Division IVa and anglerfish into Subarea IV and Division IIIa). This includes four cod, haddock and whiting stocks, five sole and plaice stocks, two megrim stocks, one anglerfish, ten Nephrops stocks, one of pollock and one of grey gurnard which was a new addition to the WG this year. Seven stocks within the remit of the WG went through the benchmarking process in 2012 and one through an Inter-benchmark Protocol. Of these, analytical assessments were agreed for cod-scow, cod-7e–k, had-7b–k, meg-46a, sol-echw and whi-scow. An interim assessment was agreed for cod-iris (while further work is being carried out) to be used to provide advice on stock status and total mortality. Little progress was made on ang-46.