American foulbrood, as the most destructive and widespread bacterial disease of honeybees, is also one of the main causes of bee extinction, but it also causes great losses in beekeeping. The causative agent Peanibacillus larvae is a sporogenic, gram-positive bacterium, extremely resistant to external conditions, especially high temperatures. Spores are also an infectious source of infection, and a dose of 10 spores is sufficient for larval infection. The use of antibiotics in the control of the disease is prohibited, due to the residues they leave in bee products, due to the possibility of recurrence of the disease itself, and the ineffectiveness of antibiotics on spores, which are an infectious form and source of infection. Control of the disease is prescribed by an order for the current year, and the most commonly ordered and most successful measure of eradication of the disease is the burning of hives with a brood, and the suffocation of adult bees. The aim of this study was to gain insight into the effect of a certain disinfectant in real time and concentrations for the vegetative form of P. larvae, and that the obtained results will be important in practical beekeeping, in the implementation of preventive and final disinfection, and will reduce disease recurrence. After the research, it was concluded that the tested agent "Bee Protect F" has a certain disinfectant effect, but insufficient for final disinfection after sanitation od disease. Since the manufacturer declares this product as mineral food with added bees, the assumption is that the use of this product can onla help in preventive disinfection.