Background: In peginterferon alpha2b (PEG-IFN 2b) and ribavirin (RBV) combination therapy for 48weeks for patients with chronic hepatitis C, it is still difficult to predict which patients will achieve sustained viral response (SVR) at the completion of this therapy. Aim: To predict SVR and non-SVR (relapse) at the end of this combination therapy by determining changes of serum hyaluronic acid (HA) levels. Methods: Eighteen patients were enrolled and their serum HA levels were measured before therapy, and after the 1st, 2nd, 3rd, and last trimesters during therapy. Results: Eleven patients achieved SVR and 7 became relapsers. All patients showed higher HA levels in the 1st trimester than the pretreatment levels. In the SVR group, 3 of 11 (27.2%) patients in the 2nd, 5 of 10 (50.0%) in the 3rd, and 9 of 11 (81.8%) in the last trimester showed lower HA levels than the pretreatment levels. By contrast, in the relapser group, none in the 2nd, 1 of 6 (16.7%) in the 3rd, and 1 of 7 (14.3%) (p<0.05) in the last trimester showed lower HA levels than the pretreatment levels. This study revealed that as the 48-week therapy went on, HA levels were more likely to fall below the pretreatment levels by the last trimester in patients achieving SVR. However, HA levels of relapsers tended to continuously be above the pretreatment levels. Conclusion: Determination of changes of serum HA levels during PEG-IFN 2b and RBV therapy predicts SVR and non-SVR at the completion of this therapy. Results: The most frequent lymphomas were with high malignancy (40%), intermediate (32.5%) and low degree (27.5%). Cryopathy was negative (87.5%). The presence of viral markers was performed soon as possible after the NHL diagnosis, at the same time (52.5%) or during the first year of evolution (32.5%). The prevalence of the HCV infection was 15%, comparable to the one in the control patients group (22.68%), admitted in a gastroenterological clinic. On the other hand, this prevalence is significantly increased compared to the one in the general Romanian population (4.9%). The patients with NHL and HCV infection belonged especially to the low and intermediate malignancy degrees; the survival was influenced by the malignancy degree and not by the presence of HCV infection. The prevalence of HBV infection in the tested patients was 2.5%, being lower than that of HCV infection (2.5% vs. 15%, p = 0.113) but comparable to the one in the general population (2.5% vs. 6.3%, p = 0.525). Conclusions: The prevalence of HCV infection in the patients having NHL was 15%, comparable to the one in the control group, but significantly increased compared to the one in the general population, leaving open the issue of a causal relationship between HCV infection and NHL.