Part of the Federal System of External Quality Assessment of Clinical Laboratory Tests named "PCR-identification of hepatitis C virus (HCV)" and aimed at detection of HCV RNA by polymerase chain reaction (PCR) assay is functioning from 2000. Ninety, 98, and 112 laboratories from more than 50 regions of Russian Federation participated in it in 2000, 2006, and 2007 respectively. Analysis of results of control samples tests, which were performed by participated laboratories, showed increasing proportion of method of amplification in the presence of fluorescent-marked probes both in real-time and in end-point regimens. In these circumstances, significant increase of specificity and sensitivity of tests was observed. In 2007, proportion of correct results obtained by the participants for tests with negative control samples was 96 - 97%, whereas during detection of HCV RNA in concentration 10(3) IU/ml the proportion of correct results was 80 - 83%. Significant proportion of laboratories, which did not detect HCV RNA in concentration 10(3) IU/ml, points on the necessity to improve sensitivity of this important method of laboratory tests.