We present the preliminary results of a study aiming at investigating the occurrence, distribution and concentration of a range of current-use and legacy pesticides in rivers and streams in Victoria, south-eastern Australia. A total of 142 pesticides were analysed in water and sediment samples collected at 97 riverine sites across Victoria. Twenty-two pesticides were detected. The triazine herbicide simazine was present in most of the water samples (84%). Highest concentrations in water were found for the herbicide terbuthiuron (1.42 ug/L) and the triazines simazine (1 ug/L) and atrazine (0.91 ug/L). These concentrations are within previous reported results in Victoria. In sediments, the pyrethroid insecticide bifenthrin (31%), and the legacy organochlorines dieldrin (25%) and pp-DDE (20%) were the most detected. Highest concentrations in sediments were found for glyphosate and its metabolite AMPA (3.3 and 2.7 mg/kg, respectively). Measured glyphosate and AMPA concentrations were above concentrations reported in the literature to negatively affect benthic communities and constitute a potential risk to aquatic organisms in the systems studied. Current analysis is underway to determine if the patterns of occurrence of the pesticides could be related to land use parameters. For this, the land use proportion for each sampled site was calculated using the Victoria Land Use Information System (VLUIS). Multivariate techniques will be used to identify relationships between land uses and pesticides occurrence and concentrations. Finally, the risk posed by the pesticides to the aquatic ecosystems studied will also be assessed using hazard quotients (HQ).