Numerous studies conducted in HCV infection over the past several years in Poland have focused on clinical course, treatment and epidemiology in selected high risk groups. Studies estimating the prevalence of HCV in the current general population are lacking. Various studies conducted in subpopulations yielding values ranging from 0.9% to over 4%. In the present paper we attempt to explain these discrepancies and assess the reliability of available data. We included prevalence studies published in 2000-2009, which could refer to the general adult population in Poland. All available studies in terms of possible conclusion about the general population suffered from systematic errors, most commonly selection bias (e.g., volunteer bias, hospital bias), or misclassification (no confirmation of detected anti-HCV). Given estimates often referred only to selected regions or age groups. Extrapolating these results to estimate the burden of illness in general population may lead to incorrect assessment, thus currently there is no scientific basis for planning screening programs and national strategies against HCV.