Expression of proliferating cell nuclear antigen (PCNA) as well as p53, bcl-2 and C-erb B-2 genes protein products on Reed-Sternberg/Hodgkin's (R-S/H) cells was analyzed by immunohistochemistry in 65 patients with Hodgkin's disease (HD). Their significance as markers of clinical malignancy and prognostic factors was evaluated. Positive reaction for PCNA was present in 57 cases (87.7%), for p53 in 42 (64.6%), for bcl-2 in 41 (63.1%), and for C-erb B-2 in 38 cases (58.5%) of HD. The high proliferate PCNA index and high expression of p53 and bcl-2 correlated with poor response to the treatment. Expression of both p53 and bcl-2 oncoproteins negatively influenced overall survival and disease free survival. Indexes of PCNA, p53 and bcl-2 were significantly higher in patients with advanced disease then in early clinical stages. In LP type of HD the lowest indexes of PCNA or bcl-2, and even lack of bcl-2 expression on R-S/H cells were observed. There was no correlation between expression of C-erb B-2 and response to the treatment, time of survival, clinical stage or histopathological types of HD. Statistical analysis let us to the conclusion, that indexes of PCNA, p53 and bcl-2 expression can be taken into consideration as a new prognostic factors in Hodgkin's disease. C-erb B-2 protein expression seems to be of no value for prognosis in HD.