The pilot testing of the Japanese translation of the European Organization for Research and Treatment of Cancer (EORTC) gastric cancer module (QLQ-STO22) was done for 10 patients (6 men; 4 women) with gastric cancer. Age ranged from 23 to 73. Five patients had a performance status (PS) of 0, 4 had a PS of 2, and 1 had a PS of 4. Five had stage IV gastric cancer. It took 20 to 40 minutes for the patients to complete the questionnaire. All stated that it did not take long a time to complete, and that each question was easy to understand as a whole. They also mentioned that the questionnaire appropriately described and represented their health condition. However, it was revealed that some linguistic revisions should be made for 5 of the 22 questions to clarify their meanings by adding examples or replacing unclear words with clearer ones. The Japanese version of the QLQ-STO22 was finalized via those revisions. We are waiting for the result of the validation study in an international field (EORTC protocol number 15001/40003) with a larger number of gastric cancer patients using standardized psychometric testing.