The aim of the study was to assess the role of serum tumour markers (NSE, Cyfra 21-1, CEA, LDH, ferritin) as a prognostic and predictive factors in 79 patients with advanced NSCLC treated with chemotherapy. Objective response to treatment was significantly more frequent in the patient with serum NSE > 12.5 ng/ml. Progression of disease was observed more often in patients with serum Cyfra 21-1 >10 ng/ml or LDH >480 U/L. CEA >3 ng/ml, LDH >480 U/L, for coefficient >1, NSE >20 ng/ml and Cyfra 21-1 >10 ng/ml had a negative impact on survival in univariate analysis. Independent negative prognostic significance of fer coefficient >1 was confirmed by multivariate analysis.