Analysis of T-cell surface markers was carried out in peripheral blood and bronchoalveolar lavage (BAL) fluid of Japanese patients with sarcoidosis to examine the influence of differing racial background. The subjects were 26 untreated patients in whom a diagnosis of active sarcoidosis had recently been established and 9 healthy volunteers, and two-color immunofluorescence analysis was performed. CD3+HLA-DR+ cells, CD4+HLA-DR+ cells, and CD4+CD29+ cells in peripheral blood and BAL fluid were significantly increased in the patients compared with the healthy volunteers, and the mean percentages increased in parallel with the extent of the radiologic stage. The percentage of CD3+HLF-DR+ cells in peripheral blood and lavage fluid also significantly correlated with serum activity of angiotensin-converting enzyme (r = 0.69, p < 0.001; r = 0.61, p < 0.001, respectively). Thus, the evaluation of these antigens' expression is an important clinical approach for the staging of the disease. However, no significant differences were found in CD3+CD25+, CD4+CD45RA+, or CD8+CD11+ cells in either peripheral blood or BAL fluid between the patients and volunteers. Our results indicated that in Japanese patients with sarcoidosis, circulating T cells are activated but CD25+ cells are not increased in peripheral blood and BAL fluid, but there is not a significant association with racial background.