Artificial sweeteners (Ass) have been used for decades as food and drink additives. ASs are not readily metabolized by humans and are excreted mostly unchanged from the human body and therefore they can be detected in high concentrations in the inflow to wastewater treatment plants. This study evaluates the occurrence and removal of saccharin in six constructed wetlands in the Czech Republic. The results revealed that saccharin was identified in 100% of samples of inflowing wastewater. The average removal of saccharin was only 42.4%, lower as compared to >90% removal of saccharin commonly achieved in activated sludge treatment plants. There was no difference in saccharin removal during the summer and winter periods. The correlation of saccharin removal with removal of major pollutants indicated a significant positive relationship with removal of COD, relationships to other major pollutants removal were not significant. Saccharin removal was positively related (p < 0.05) to dissolved oxygen concentration in the inflow wastewater and outflow values of redox potential. This is the first study that evaluates the removal of saccharin in constructed wetlands and therefore, more research is needed to confirm these preliminary results. (C) 2016 Elsevier B.V. All rights reserved.