c-myc protein p62 in human gastric carcinomas was studied by immunohistochemistry using an antiserum raised against the C-terminal portion of the human c-myc gene protein. No immunoreactivity of c-myc p62 was detected in tumor cells of 27 early carcinomas, while c-myc p62-positive tumor cells were observed in 51 (36.4%) of the 140 advanced carcinomas. Many stromal cells including macrophages and fibroblasts around the tumors showed various degrees of c-myc p62 immunoreactivity. Localization of c-myc p62 was predominant in the cytoplasm of tumor cells and stromal cells. The prognosis of patients with p62-positive stromal cells was significantly better than that of patients with p62-negative stromal cells.