In the context of the Marine Strategy Framework Directive and the Water Frame Work Directive, the chemical monitoring of marine and fresh waters has become a crucial point. Thus, there is a need to apply monitoring methods in surface waters taking into account temporal and spatial aspects with a limited cost and a relatively ease of use by non-expert routine laboratories. Since the 1990’s, passive samplers (PSs) have been widely developed to measure contaminants in surface waters. These tools present many advantages since they allow to (i) give an integrated measure of the contamination over the period of deployment, (ii) avoid problems of contamination linked to sampling procedure via bottles and/or pre-treatment of the sample, (iii) preconcentrate pollutants inducing a decrease of limit of quantification and (iv) avoid complex matrix such as saline waters representing problems for analysis. Nevertheless, there is still a lack of quality assurance and control procedures to improve the reliability and the comparability of results obtained by passive sampling (PS). Indeed, very few in situ intercomparison exercises on PSs have been performed until now. In 2010, an AQUAREF in situ intercomparison exercise that included several types of passive samplers for priority pollutants (PAH, pesticides and metals) was conducted in French surface and coastal waters. This first trial allowed to evaluate the representativeness of different tools for in situ monitoring and showed that despite various strategies and various tools, global uncertainties were generally low and satisfying (Miege et al., 2012). This presentation focuses on the results obtained for the monitoring of metals via PSs during this intercomparison exercise. Two trials were conducted over 7 days periods in the Rhône River at Ternay and in the Thau Lagoon. Ten and six laboratories participated to the trials at Ternay and Thau sites, respectively. Results were reported for eight metals (Cd, Cr, Cu, Ni, Pb, Zn, Mn and Co). Mainly DGT open pores, as well as DGT restricted pores and Chemcatcher® were exposed. We studied more precisely the interlaboratory variability at each step of the DGT deployment and analysis for the determination of a time weight average concentration (TWAC). Thus, results of laboratory and field blanks, reference solutions, and calculation methods were explored to identify parameters influencing the variability of metal TWAC measurements. This enables us to define the main recommendations for the use of PSs by routine laboratories.