Introduction. In France, surveillance of hepatitis C screening activities has been conducted since 2000 by a network of volunteer laboratories (Rena-VHC). To assess the representativeness of this network’s results, a supplementary survey was conducted in 2006. Methods. This survey was conducted using a random sample of laboratories. By accounting for the sampling plan and applying a weighting adjustment, national estimates of screening activity in 2005 were obtained. Rena-VHC data were collected according to the standard protocol. Representativeness was assessed by comparing indicators (average number of anti-HCV serology tests, proportion of positive serology tests, referred to as IGP) calculated for Rena-VHC and estimated for all laboratories. Results. The total number of serological tests performed by French laboratories is estimated at 5.5 million tests (95% CI: 4.6 million–6.5 million). For public laboratories, the average number of serological tests per Rena-VHC laboratory (3,889 tests) falls within the 95% CI: (2,320 tests – 5,462 tests) of the national estimates. Similarly, the Rena-VHC prevalence rate (3.6%) falls within the national estimates: 95% CI (3.0% – 4.1%). Regarding private laboratories, the average number of serology tests performed per Rena-VHC laboratory (1,745 tests) is higher than the national estimates: 95% CI (633 tests – 844 tests), while the Rena-VHC prevalence rate (1.6%) is lower: 95% CI (1.7% – 2.1%). Conclusion. Although designed for a different purpose (monitoring screening trends), Rena-VHC appears to be a good tool for estimating screening activity in public laboratories. However, it does not perform well for private laboratories. (R.A.)