Large granular lymphocyte leukaemia (LGL leukaemia) is a rare, chronic lymphoproliferative bone marrow disease which can be considered a subtype of chronic T-cell lymphocytic leukaemia (T-CLL). We describe three patients with large granular lymphocyte leukaemia. They all suffered from chronic disease with neutropenia and relative lymphocytosis. An expansion of mature lymphocytes with the CD3+, CD8+, CD57+ immunophenotype was demonstrated in all three patients. Two patients had a history of recurring infections. Serological findings compatible with rheumatic disease were present in all three patients, and two suffered from rheumatoid arthritis. We have made a brief survey of this disease, which is characterized by relative or absolute lymphocytosis, neutropenia, and an increased risk of infection. Rheumatoid arthritis and other associated autoimmune manifestations occur frequently. Large granular lymphocyte leukaemia should be considered a possible diagnosis in patients with chronic neutropenia and relative lymphocytosis, in particular if rheumatic manifestations are also present. Flow cytometric immunophenotyping is a sensitive method in diagnosing this disease.