Ankle oedema and abdominal swelling suddenly developed in a 55-year-old woman who also had lymphadenopathy in the neck, axillae and groin. Ultrasonography demonstrated hepatosplenomegaly, ascites and pleural effusions. Histological examination of some lymph-nodes from the axilla and groin revealed angioimmunoblastic lymphadenopathy (low-malignant peripheral T cell lymphoma). Bone-marrow biopsy was undertaken because of a normocytic anaemia (haemoglobin 4.9 g/dl) requiring blood transfusion, thrombocytopenia (5000/microliters) and monoclonal IgG gammopathy. This showed lymphoma-associated secondary myelofibrosis. Treatment with prednisone (2 mg/kg daily for 8 weeks) and vincristine (1 mg/m2 once weekly for 4 weeks) brought about partial remission of the angioimmunoblastic lymphadenopathy with normalization of the clinical and laboratory findings, the splenohepatomegaly regressed, and there was only a small amount of ascites. Four months after onset of the illness bone-marrow biopsy also showed regression of the myelofibrosis.