Grab sampling may be scarcely adequate to evaluate the impact on surface waters of pesticides used in agriculture because of its poor spatio-temporal representativeness compared to the high variability of the contamination patterns. In the present study, passive samplers and biological indicators have been applied together at the catchment scale in order to evaluate both concentration levels and in situ impact of pesticides in aquatic environments. Two passive samplers were deployed to monitor respectively hydrophobic to moderately hydrophilic or hydrophilic pesticides. In parallel the biological approach consisted in an in situ biomonitoring with i) a caging methodology resorting to a highly ecological relevant amphipod species, Gammarus Fossarum and ii) the study of microbial and macro-invertebrate communities as well as phototrophic periphytic communities. All these tools have been applied in two agricultural catchments. Results showed the high coherence of chemical and biological tools responses. All of them were able to reflect the spatial contamination gradients as well as the specific contamination and impact associated.