A case of metastatic tumor of right spermatic cord in a 54-year-old man is reported. He visited our department with the complaint of a painless mass in right inguinal lesion. The initial diagnosis was a right spermatic cord tumor, and then orchiectomy was performed. Since pathological findings showed a poorly differentiated adenocarcinoma, further examinations were done, postoperatively. An upper gastrointestinal series revealed the presence of gastric carcinoma. Thus, these results suggested that the spermatic cord tumor was a metastatic lesion from the gastric carcinoma. Forty eight cases of metastatic tumor of the spermatic cord have been reported in our country. In 26 of these cases, gastric carcinoma metastasized to the spermatic cord.