The presence of tumor-infiltrating lymphocytes (TILs) and the expression of adhesion molecules were examined in 12 glioma tissues. Most TILs were T lymphocytes, and both cytotoxic/suppressor and helper/inducer T lymphocyte phenotypes were found. Neural cell adhesion molecule was intensely expressed in 11 gliomas, and intercellular adhesion molecule-1 (ICAM-1) in seven. Many TILs were found only in gliomas expressing ICAM-1, but there was no relationship with clinical course in the patients.