An extensive body of research concerns the valuation of EU certification schemes of quality based on the origin of food products. This literature focuses mainly on stated preferences (SPs) and reported behaviours by the consumers. We combine consumers' SPs, obtained through a conjoint ranking experiment, with revealed preferences (RP), obtained through a retail scanner database. We evaluate SPs as predictors of RP, and investigate whether SPs and RPs are consistent. Dry-cured ham in Spain is chosen as the anchor product, mainly because of its broad customer base and long history of origin certification. A 'trick' nested logit model with non-identical and identical samples of consumers is estimated to answer each of the objectives. Results show that, irrespective of the analysed samples, SP can predict general market trends and choices but not accurately predict market shares, and that consumers' actual behaviour is partly consistent with their SPs. We find that consumers prefer ham produced in Teruel, compared with unspecified Spanish origin. Quality Certification and a Distributor's Brand are preferred over the alternatives of no quality label or identified with a brand owned by the producer. Interestingly, SPs for the Quality Certification and the distributor's brand lead to an over- and under-estimation, respectively, of the market share. Copyright (c) 2010 The Authors. Journal compilation (c) 2010 The Agricultural Economics Society.