Recently, the JAK2 V617F mutation has been reported in high proportions of chronic myeloproliferative disorders, including polycythemia vera. To see whether the JAK2 V617F is important in the pathogenesis of lymphoid malignancies, this study analysed the occurrence of the JAK2 V617F mutation in 117 non-Hodgkin lymphomas (NHLs) by a single strand conformation polymorphism assay. However, there was no JAK2 V617F mutation in the NHLs and the data suggest that the JAK2 V617F mutation may not play a role in the development of NHL.