This work examines the methane production potential for the anaerobic co-digestion of swine manure (SM) with winery wastewater (WW). Batch and semi-continuous experiments were carried out under mesophilic conditions. Batch experiments revealed that the highest specific methane yield was 348 mL CH(4) g(-1) COD added, obtained at 85.4% of WW and 0.7 g COD g(-1) VS. Specific methane yield from SM alone was 27 mL CH(4) g(-1) COD added d(-1). Furthermore, specific methane yields were 49, 87 and 107 mL CH(4) g(-1) COD added d(-1) for the reactors co-digesting mixtures with 10% WW, 25% WW and 40% WW, respectively. Co-digestion with 40% WW improved the removal efficiencies up to 52% (TCOD), 132% (SCOD) and 61% (VSS) compared to SM alone. These results suggest that methane can be produced very efficiently by the co-digestion of swine manure with winery wastewater. (C) 2011 Elsevier Ltd. All rights reserved.