Sequential skin biopsies were obtained from five patients receiving chemotherapy for acute myelocytic leukemia. The first specimen was taken on the fourth day of initial chemotherapy and subsequent specimens were obtained at weekly intervals thereafter, until discharge. In all cases, clinically normal skin was selected as the biopsy site. A panel of monoclonal antibodies was applied to frozen tissue sections, including anti-intercellular adhesion molecule-1 (ICAM-1), anti-lymphocyte function-associated antigen-1 (LFA-1), and anti-HLA-DR. Bound antibody was detected using the avidin-biotin complex method. Endothelial cell expression of ICAM-1 and lymphocyte expression of LFA-1 were unaffected over the course of the ensuing, profound marrow aplasia. This finding suggests that this mechanism of lymphocyte trafficking in the skin remains operational despite the administration of antileukemic agents.