This study aims to compare and correlate the concentrations of pharmaceutical found in hospital wastewater via chemical analysis with those estimated based on consumption data. For this reason, wastewater samples were collected from different points of the sewerage system serving a Greek hospital and analysed using LC-QTOF-MS for more than 200 compounds. Consumption data were collected in parallel from the hospital pharmacy and used for finding the Predicted Environmental Concentrations of pharmaceuticals in hospital wastewater. The measured concentrations on found pharmaceuticals were different between different days and point of sampling. Significant agreement was found between wastewater analysis and consumption data for some pharmaceuticals, while poor correlation for others.