The results of serological and molecular screening tests for HCV performed by Polish Blood Transfusion Service between 1994 and 2003 are presented. Serological tests were performed in 4,233,119 donors. The average frequency of anti-HCV was 0,48%. The frequency of anti-HCV was higher in first time donors (0,86%) than in repeat donors (0,23%). In both groups a decreasing trend in anti-HCV frequency was observed--4% annually in the group of candidates for donors and 21% annually in repeat donors. Molecular methods for identification of HCV infection in serologic window period were introduced in 2000. RNA HCV was detected in 51 out of 2,915,299 (0,002%) anti-HCV negative plasma samples. The frequency of HCV infection markers is in Poland higher than in most European countries. However, a decreasing tendency of HCV markers detection, especially in repeat donors is observed.