Concentrations of aquatic insecticides have increased due to their overuse in modern agriculture. The choice of an appropriate water treatment method for insecticide removal depends on the type of insecticide and the effectiveness of the treatment process. The aim of this paper is to consider the adsorption of imidacloprid neonicotinoids on the surface of a solid TiO2 catalyst as one of the methods for pretreatment of polluted water, and to determine the influence of individual process conditions on the effect by means of experiments. According to the experimental design (Box-Behnken design), the adsorption reactions were carried out with different combinations of selected parameters, which were randomly generated. These parameters were the pH of the solution, the concentration of the imidacloprid solution and the recirculation of the solution, i.e. the hydrodynamic conditions. The preparation of the catalyst, on the surface of which the adsorption took place, consisted of preparing a thick suspension of the photocatalyst P-25 TiO2 and the filler Procol until the desired texture was obtained, and the mixture was applied to sandpaper of desired dimensions. The analysis of the samples was carried out using an HPLC (High Performance Liquid Chromatography) instrument and the values obtained were processed by the statistical "ANOVA" analysis. The results showed that the pH of the solutions had the greatest influence on the range of the adsorption, and the statistical analysis proposed a quadratic model indicating the influence of two parameters on the adsorption process, namely pH values and solution concentrations. According to the calculated values, the maximum adsorption range was 20%.