Research addressing the occurrence, fate and effects of pharmaceuticals in the aquatic environment has expanded rapidly over the past two decades, primarily due to the development of improved chemical analysis methods. Significant research gaps still remain, however, including a lack of longer term, repeated monitoring of rivers, determination of temporal and spatial changes in pharmaceutical concentrations, and inputs from sources other than wastewater treatment plants (WWTPs), such as combined sewer overflows (CSOs). In addressing these gaps it was found that the five pharmaceuticals studied were routinely (51–94% of the time) present in effluents and receiving waters at concentrations ranging from single ng to μg L−1. Mean concentrations were in the tens to hundreds ng L−1 range and CSOs appear to be a significant source of pharmaceuticals to water courses in addition to WWTPs. Receiving water concentrations varied throughout the day although there were no pronounced peaks at particular times. Similarly, concentrations varied throughout the year although no consistent patterns were observed. No dissipation of the study compounds was found over a 5 km length of river despite no other known inputs to the river. In conclusion, pharmaceuticals are routinely present in semi-rural and urban rivers and require management alongside more traditional pollutants. Display omitted Pharmaceuticals were routinely present in effluent and receiving waters.Mean concentrations were in the range of tens to hundreds ng l-1.Peak concentrations reached almost 5 μg l-1.Combined sewer overflows (CSOs) are a source of pharmaceuticals.No dissipation of pharmaceuticals was found over a 5 km length of river. A range of pharmaceuticals were routinely present in effluent and receiving waters and were not found to dissipate over a 5 km length of river.