Procaine, a tertiary amino ester of an aromatic acid, is one of the most frequently present pharmaceuticals in wastewater. Due to its high hydrophilicity and low bioavailability, pharmaceuticals are very difficult to remove from wastewater using conventional methods. For this reason, the focus is placed on advanced oxidation processes that generate reactive species capable of removing or reducing the concentration of contaminants. Photocatalysis is increasingly being used as an environmentally friendly method and is based on the use of the solar spectrum with a photocatalytic material. The most commonly used photocatalytic material is titanium dioxide (TiO2). This oxide is widely used due to its inertness, high photostability, non-toxic properties, and high photoactivity. Such a material can be doped with carbon nanotubes (MWCNT), which leads to improved photocatalytic activity. In this study, many factors such as the initial concentration of reactant, oxygen concentration, pH, type of catalyst and light intensity were investigated on the process of photocatalytic degradation of procaine. When using a TiO2 photocatalyst, the optimal conditions for photodegradation are achieved at a procaine concentration of 5 mg dm^-3 and a pH value of 7, while using the TiO2/CNT photocatalyst, the optimal conditions are achieved at the same procaine concentration and a pH value of 4. Furthermore, analysis of variance examined the significance of the model, and using response surface methodology, it was concluded that temperature and pH value of the solution are significant parameters of the model. The kinetics of photocatalytic degradation were investigated by adding bicarbonates, nitrates, chlorides, and humic acids. It was also found that the degradation kinetics of procaine is slowed down by the simultaneous influence of ions and humic acids. When using a real water matrix, the half-life is longer than the half-life in MilliQ water, which is due to the presence of other contaminants and competitive binding to the active sites of the photocatalyst. The degradation of procaine with the TiO2 photocatalyst leads to three degradation products, while four degradation products are formed with the TiO2/MWCNT photocatalyst, whose structures and degradation mechanism were proposed after MS/MS analysis. The software tool T.E.S.T. was used to estimate the toxicity of procaine and its degradation products.