Telomerase activity has been demonstrated in various types of cancers including lymphoid neoplasms. The tumour specificity of telomerase activity has been a subject of debate since the description of detectable enzymatic activity in non neoplastic tissues. We and others have demonstrated that such activity was present in non Hodgkin's lymphomas as well as in reactive hyperplastic lymph nodes and tonsils. However, we at the same time were surprised by the absence of telomerase activity in most cases of Hodgkin's disease. We have extended our previous study by adding additional cases and confirm that in the majority of cases, Hodgkin and Reed-Sternberg cells lack telomerase activity (only 2 cases positive out of 20). These results may indicate that the tumour cells of Hodgkin's disease evolve different pathways for maintaining the length of their telomeres during the process of becoming immortal.