This study is the first to investigate the pharmaceutical burden from point sources affecting the UNESCO Biosphere Reserve Kristianstads Vattenrike, Sweden. The investigated Biosphere Reserve is a >1000 km2 wetland system with inflows from lakes, rivers, leachate from landfill, and wastewater-treatment plants (WWTPs). We analysed influent and treated wastewater, leachate water, lake, river, and wetland water alongside sediment for six model pharmaceuticals. The two WWTPs investigated released pharmaceutical residues at levels close to those previously observed in Swedish monitoring exercises. Compound-dependent WWTP removal efficiencies ranging from 12 to 100 % for bendroflumethiazide, oxazepam, atenolol, carbamazepine, and diclofenac were observed. Surface-water concentrations in the most affected lake were ≥100 ng/L for the various pharmaceuticals with atenolol showing the highest levels (>300 ng/L). A small risk assessment showed that adverse single-substance toxicity on aquatic organisms within the UNESCO Biosphere Reserve is unlikely. However, the effects of combinations of a large number of known and unknown pharmaceuticals, metals, and nutrients are still unknown. Micropollution of aquatic habitats due to anthropogenic activities is considered one of the major future environmental challenges because it may lead to adverse effects on a number of species (Schwarzenbach et al. 2006), and even cause a decrease in species richness and evenness of entire habitats (Johnston and Roberts 2009). Especially the mixture of compounds that work in concert, such as the release of a multitude of pharmaceuticals into the environment, has received increased attention lately (Celander 2011; Galus et al. 2013) due to the still relatively unknown effects on biota and ecosystems. We recently reported on the occurrence and the principal environmental pollution pathways of pharmaceuticals on the well-known but vulnerable Balearic Island Mallorca (Spain), which is visited by 14 million tourists each year (Rodríguez-Navas et al. 2013). Here wastewater-treatment plant (WWTP) effluents containing pharmaceutical residues ended up in marine water bodies, whereas leaching from landfills was a minor source of pharmaceuticals to groundwater aquifers. On Mallorca, measures are necessary to protect groundwater, which is used as drinking water, but it is also important to conserve aquatic environments for coming generations because contamination of such habitats may cause chronic stress, altered behaviour, and, in the worst case, extinction of wild animal populations including fish (Kidd et al. 2007; Brodin et al. 2013; Arnold et al. 2013; Bean et al. 2014). Consequently, the deterioration of such environments is a threat to both the fishing industry and tourism and therefore would have a direct consequence to the income of hundreds of thousands of Mallorquin people if a decrease is seen in the number of visitors. Now, for the first time, we report on pharmaceutical sources and sinks influencing an ecologically unique area called the Biosphere Reserve Kristianstads Vattenrike (Vattenriket for short). The biosphere is 1040 km2 (Fig. 1) and located in the southern most part of Sweden, Region Skåne, and was the first Biosphere Reserve established in Sweden (in 2005). Only five Biosphere Reserves in Sweden are officially recognized by the United Nations agency UNESCO and run under the UNESCO program Man and Biosphere (Kristianstad Vattenrike MAB 2015). This system of open-water bodies covers most of the municipality of Kristianstad including inland forests and water systems all of the way to Hanöbukten bay with rich wetlands lining the largest river in the region, Helge Å, thus creating a large number of habitats. At least 38 fish species have been found in the waters of this truly unique area (Vattenriket Kristianstad Municipality 2015). ; This study is the first to investigate the pharmaceutical burden from point sources affecting the UNESCO Biosphere Reserve Kristianstads Vattenrike, Sweden. The investigated Biosphere Reserve is a >1000 km(2) wetland system with inflows from lakes, rivers, leachate from landfill, and wastewater-treatment plants (WWTPs). We analysed influent and treated wastewater, leachate water, lake, river, and wetland water alongside sediment for six model pharmaceuticals. The two WWTPs investigated released pharmaceutical residues at levels close to those previously observed in Swedish monitoring exercises. Compound-dependent WWTP removal efficiencies ranging from 12 to 100 % for bendroflumethiazide, oxazepam, atenolol, carbamazepine, and diclofenac were observed. Surface-water concentrations in the most affected lake were ≥100 ng/L for the various pharmaceuticals with atenolol showing the highest levels (>300 ng/L). A small risk assessment showed that adverse single-substance toxicity on aquatic organisms within the UNESCO Biosphere Reserve is unlikely. However, the effects of combinations of a large number of known and unknown pharmaceuticals, metals, and nutrients are still unknown.