Background: About 15-20% of patients with advanced stage Hodgkin lymphoma (HL) still die following relapse or progressive disease and a similar proportion of patients are over-treated, leading to treatment-related late sequelae, including solid tumors and organ dysfunction. We analyzed telomere maintenance mechanisms (TMMs) of HL cell lines as well as the samples from HL patients treated with standard therapy and compared the TMMs with favorable and unfavorable clinical outcome. Materials and Methods: Frozen lymph node samples obtained from 38 HL patients during diagnostic lymph node biopsy and from 24 patients with lymphadenitis were entered in this study. All HL patients were stage I (84.2%) and II (15.8%) with mean age of 36.7 years and 94.7% were nodular sclerosis. Seven HL cell lines were used as a positive control. Telomerase activity (TA) and alternative lengthening telomere (ALT) profile were assessed as well as Epstein Barr Virus (EBV) status and protein expression levels. The TMMs were correlated to clinical outcomes of patients (10.3 years) as well as to radiation sensitivity of HL cell lines. Results: The major finding of this study is the presence of both TA and ALT mechanisms in selected lymph nodes of HL patients. This TMMs heterogeneity was confirmed in HL cell lines. Hodgkin and Reed Sternberg (HRS) cells demonstrated an ALT profile, while the small cells exhibited a higher telomerase activity. We identified in the same tumor lymph node HRS cells containing ALT-associated PML bodies, a hallmark of ALT, and separate small cells expressing telomerase. Similarly, in HL cell lines, a high level of TA was detected in L428 and SUP-HD1. L1236 cell line demonstrated a lower TA and presented an ALT profile. The latent membrane protein (LMP1) staining revealed the presence of EBV genome in HRS cells in 13 lymph nodes (34.2%). A higher expression of TRF2/PML (ALT profile) and CD68 in EBV positive patients was correlated with Overall Survival (p=0.02), Freedom From Progression (p=0.02) and Event Free Survival (p=0.003). ALT HL cell lines demonstrated a lower radiation sensitivity as compared to TA HL cell lines. Conclusion: The presence of both TMMs (TA and ALT) in HL lymph nodes and HL cell lines is a singular oncology phenomenon. TMMs, related to tumor microenvironment in HL lymph nodes, are associated with treatment response and survival of HL patients.