A method of treating a patient who has gastric cancer includes administering to said patient a composition containing a population of activated T cells that selectively recognize cells in the patient that aberrantly express a peptide. A pharmaceutical composition contains activated T cells that selectively recognize cells in a patient that aberrantly express a peptide, and a pharmaceutically acceptable carrier, in which the T cells bind to the peptide in a complex with an MHC class I molecule, and the composition is for treating the patient who has gastric cancer. A method of treating a patient who has gastric cancer includes administering to said patient a composition comprising a peptide in the form of a pharmaceutically acceptable salt, thereby inducing a T-cell response to the gastric cancer.