INTRODUCTION: Search for new prognostic markers in order to improve prognostic accuracy and predict clinical outcome at the time of dia-gnosis has recently become one of the major trends in chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS, AIM OF STUDY: The aim of our study was assessment of selected markers of apoptosis and angiogenesis and their potential as new prognostic factors. We evaluated serum levels of tumor necrosis factor α (TNFα) and transforming growth factor β 1 (TGFβ1) using commercially available enzyme linked immunosorbent assay; furthermore, we quantified expression of type II receptor for transforming growth factor beta (TGFβRII) and type 2 receptor for fibroblast growth factor 2 (FGFR2) on CLL cells using flow cytometry analysis in 75 previously untreated patients with CLL (47 males and 28 females, median age, 65 years, range 38- 82) and healthy donors. RESULTS: We found significantly elevated TNFα in patients with CLL compared to the control group (p < 0.0001); high expression of TNFα was associated with unfavourable prognosis: significantly higher concentrations were found in patients with Rai highrisk group compared to low and intermediate-risk group (p = 0.0008 and p = 0.0097), with high serum β2- microglobulin (p = 0.045), massive lymphadenopathy (p = 0.0083), unmutated genes for variable region of immunoglobulin heavy chain (IgVH) (p = 0.041) and unfavourable cytogenetic aberrations (p = 0.0014). In addition, patients with progressive CLL had significantly higher TNFα than those with stable clinical course (p = 0.0009); time to treatment was significantly shorter in patients with higher TNFα (p = 0.0049). Higher TGFβ1 concentrations were associated with favourable subgroups: with Rai low risk group compared to high risk group (p = 0.011), patients without massive lymphadenopathy (p = 0.041), patients with mutated IgVH (p = 0.012) and ZAP 70 negativity (zeta associated protein of 70 kilodaltons) (p = 0.044). Patients with progressive CLL had significantly lower TGFβ1 levels than those with stable course (p = 0.0014) and time to treatment was significantly longer in patients with higher TGFβ1 (p = 0.016). Patients with Rai high risk group had significantly lower TGFβRII expression than those with low risk group (p = 0.022). The prognostic significance of FGFR2 was not found. Significant and independent prognostic factors for overall survival were high serum concentrations of TNFα and massive lymphadenopathy (p = 0.036, resp. p = 0.047). CONCLUSION: Based on our results, TNFα and TGFβ1 possess prognostic significance in CLL; further research in this direction may also be important therapeutically, because these signal pathways could serve as possible treatment targets.