Pharmaceuticals can interact negatively in an uncontrolled and unpredictable manner with microorganisms and aquatic animals, and additionally pose a threat of contamination of drinking water sources. The purpose of the study was to determine the effectiveness of the decomposition of pharmaceutical residues contained in municipal wastewater, using an active ultrasonic field, in terms of water resource management. The novelty of this work is to demonstrate that there is a potential possibility of implementing technology based on the use of an ultrasonic field in the wastewater treatment process and, as a result, increasing the susceptibility to decomposition of diclofenac and ketoprofen present in municipal wastewater using the active action of an ultrasonic field with a high nominal power of 750 W and a low frequency of approximately 20 Hz at an ultrasonic field intensity of 1.72 Wcm-2. Pharmaceuticals belonging to the group of non-steroidal anti-inflammatory drugs, i.e.: diclofenac and ketoprofen, were selected for the study. The degree of concentration reduction of selected pharmaceuticals was determined by quantitative analysis of pharmaceuticals present in municipal wastewater. It was observed that subjecting pharmaceuticals to exposure to ultrasounds influenced the decrease in their concentration. With the increase in the applied sonification time, a decrease in the toxicity of the tested pharmaceuticals was observed, i.e. for diclofenac, from 83 to 91% for 120s and for ketoprofen from 94 to 99% for 240s. It should be noted that the sonication of sewage sludge by initiating the phenomenon of ultrasonic cavitation and generating highly reactive hydroxyl radicals affects the reduction of selected pharmaceuticals, which determines the implementation of the tested technology on a larger scale.