The uncontrolled use of pesticides causes them to accumulate in the environment and pollute soil, air and water, but also has numerous consequences for human and animal health. Pesticides are difficult to remove from wastewater using conventional methods because they are very stable compounds. Nowadays, advanced oxidation processes are increasingly used for their purification, focusing on heterogeneous photocatalysis. The aim of this study was to investigate the photocatalytic degradation of the neonicotinoid insecticide acetamiprid in aqueous solution. The experiments were carried out in a 250 mL batch reactor with recirculation of the reaction mixture and using a UVA-LED radiation source with a heterogeneous UVC modified perlite-based TiO2 photocatalyst. The initial concentration of acetamiprid was 10 ppm. The influence of catalyst type, reaction mixture volume (100, 150 and 200 mL) and radiation intensity (31.5, 31.8 and 32 V) on the reaction efficiency was investigated. Before performing the experiments, an experimental design was prepared using the software package Design-Expert and the progress of acetamipride degradation was monitored using high performance liquid chromatography. From the obtained experimental data, the photocatalytic reactions efficiency, the reaction rate constants according to the proposed Langmuir-Hinshelwood kinetic model of the reaction were calculated. The experimental results have shown that the conversion of the reaction is significantly affected by the type of catalyst, i.e. the method used to immobilize the photocatalyst on perlite granules. The highest conversions were obtained with catalysts obtained by impregnation methods, and for catalysts obtained by sol-gel conversion methods, the conversions were quite low. It was also found that the highest conversions were obtained with the highest radiation intensity and the smallest volume of reaction mixture.