We analysed the cell surface expression of chemokine receptors and natural killer receptors (NKRs) in addition to conventional T- and natural killer (NK)-cell markers in patients with lymphoproliferative disease of granular lymphocytes (LDGL), and compared results between NK- and T-LDGL subgroups. The subjects of this study were 15 LDGL patients: four NK-LDGL and 11 T-LDGL [six CD8(+) T-cell receptor (TCR) alphabeta(+), four CD4(+) TCRalphabeta(+) and one CD8(+) TCRgammadelta(+)] cases. Flow cytometric analysis showed that the expanding cells had a common phenotype, CD45RA(+) CD27(-) CD28(-) CCR7(-), in NK- and T-LDGL patients irrespective of differences in TCR status. There were no marked differences in the expression patterns of chemokine receptors between NK- and T-LDGL patients. Although restricted NKR subsets were expressed on both NK- and T-large granular lymphocytes (LGLs), CD94 was the most widely expressed marker. These findings may be unique to cells of LDGL cases, because normal CD56(dim) NK cells frequently express killer cell immunoglobulin-like receptors. Furthermore, analysis of NKR expression was repeated over an interval of more than 6 months, and fluctuations of NKR repertoire in the LGL clones were minimal.