The ICES Working Group on the Assessment of Southern Shelf Stocks of Hake, Monk and Megrim (WGHMM) met in ICES Headquarters during May 10-16 2012. There were 21 stocks in its remit distributed from ICES Divisions IIIa to IXa though mostly distributed in Sub Areas VII, VIII and IX. There were 18 participants (of whom 3 participated part time and 3 by correspondence). The group was tasked with carrying out stock assessments and catch forecasts and providing a first draft of the ICES advice for 2013 for all stocks including 9 functional units for Nephrops. In addition, 5 new stocks were also added to the terms of reference in 2012. A number of WGHMM stocks underwent the benchmark process in 2012. Anglerfish stocks (L.piscatorius and L.budegassa) in VIIIc, IXa and in VIIb-k, VIIIa,b,d and megrim (L.whiffiagonis) in VIIb-k, VIIIa,b,d were considered by WKFLAT_2012 with new assessment approaches being agreed for L.piscatorius in VIIIc, IXa and for megrim in VIIb-k, VIIIa,b,d. Nephrops FUs 23-24 and 26-27 were also considered by the Inter-Benchmark Protocol IBPNeph_2012 although no firm conclusions were reached by this group. A number of issues significantly constrained the group’s ability to address the terms of reference this year, most notably the recall of all Spanish commercial data for 2011 that had previously been supplied. Alternative ‘official’ data were subsequently supplied to the group but for a number of reasons these data could not be used in the assessments. This meant that for 19 of the 21 stocks no update assessment could be conducted this year. In these instances the group adopted one of two approaches depending on the status of the assessment for the stock concerned (see section 1.4.1 for further details). Five new stocks were included in the terms of reference for 2012. Confirmation that these stocks would be included for consideration by the WGHMM was received prior to the meeting but gave little opportunity to arrange for stock co-ordinators and preparation of data prior to the meeting. Relatively little progress was made for the new stocks in 2012. The group discussed approaches for improving the information for these stocks and for integrating them more appropriately into the report next year. As last year this information is contained in an annex to the final report (Annex R). Section 1 of the report presents a summary by stock and discusses general issues. Section 2 provides descriptions of the relevant fishing fleets and surveys used in the assessment of the stocks. Sections 3 to 12 contain the single stock assessments. Several annexes follow.