Background: Mammalian meat allergy is not common in adults, but increasing in recent years. Although the pathogenic mechanisms are not understood, various immunological and non-immunologic mechanisms were suggested. The aim of this study was to evaluate clinical and immunological characteristics of the patients with delayed hypersensitivity developed after consumption of meat. Methods: Thirty patients with delayed hypersensitivity to beef and/or pork (developed 2 hrs later) were enrolled from Ajou University Hospital. Skin prick tests were performed with commercial beef and pork extracts (Bencard, Bradford, UK) and considered positive if they produced a wheal with a diameter ≥ 3 mm. Serum specific IgE antibodies to beef, pork and galactose- α-1,3- galactose (α-gal) were measured by immunoCAP (Phadia, Sweden). Serum specific IgG1 and G4 antibodies to beef and pork were measured by ELISA. Results: Twenty (66.7%) were female and 25 (83%) were atopics. The most common symptoms were urticaria/angioedema (83.3%) followed by anaphylaxis (16.7%) and gastrointestinal symptoms (13.3%). The skin prick test to beef and pork extracts showed negative results in all, while serum specific IgE to beef and pork was found in 16.7% and 10% of them. The specific IgE to α-gal was found in 3(10%) patients. High serum specific IgG1 to beef and pork was detected in 2(6.7%) and 3 patients (10%), while serum specific IgG4 was detected in 3(10%) and 1 patient (3.3%). Conclusion: We suggested that IgE mediated response to α-gal as well as IgE and IgG responses to beef and pork may induce delayed hypersensitivity to meat. Future investigations will be needed on cellular immune mechanisms. This study was supported by a grant from the Korea Science and Engineering Foundation (KOSEF) funded by the Korean government (MEST, 2009-0078646).