Azithromycin (AZ) is a wide-spectrum macrolide antibiotic which presence is detected in the aquatic environment. It belongs to the group of „new emerging contamintants“ and it is very difficult removed by conventional wastewater treatment methods. Even though pharmaceuticals are generally present in the environment in low concentrations, their long-term discharge can leave irreversible consequences on all environmental constituents and also on human health. In order to prevent their entry into the environment, development and application of new and effective methods will be required and which, in combination with conventional treatment methods, will be effective in removing these substances. One of the methods that has proved effective in removal of pharmaceuticals are advanced oxidation processes. The aim of this paper was to determine the toxicity of aqueous azithromycin solution with initial mass concentration of 10 mg/L after performing two types of advanced oxidation processes, direct UV photolysis and photocatalysis with TiO2 by using UV-A and UV-C radiation. The toxicity determination was performed by using a bioluminescent method for the determination of acute toxicity with Vibrio fischeri bacteria. Also, by high performance liquid chromatography-tandem mass spectrometry, degradation products were detected and identified after the treatment with advanced oxidation processes. In this case, toxicity determination is of crucial importance since the established degradation products may be more toxic than the starting substances. Studies have shown that none of the tested solutions of azithromycin after the application of advanced oxidation processes is toxic, regardless of the presence of formed degradation products. The formation of degradation products was recorded during the photolytic process with TiO2 at a wavelength of radiation of 254 nm.