SummaryWe report the findings in 21 Belgian patients (12 males and 9 females, median age 61 years) with LGLPD. Symptoms at presentation included infection (n=9), weight loss (n=5), asthenia (n=9), pruritus (n=2) and arthralgia (n=7). Four patients were asymptomatic. The main clinical findings were hepatomegaly (n=5), splenomegaly (n=8), lymph node enlargement (n=3) and arthritis (n=5). All patients had an increased LGL count associated with anemia (n= 12), neutropenia (n=17), often<0, 5. 107L (n=10) and thrombocytopenia (n=6). Three patterns of lymphocyte surface markers were observed: CD,* CD; (14 patients), CD/CD;/ (5 patients) and CD,* CD/g’(1 patient). An abnormal karyotype was found in 2 patients. T-cell receptor gene was rearranged in all cases tested (9/9).Our findings are in agreement with recent data from the literature.