In years 2012–2014 on the horticultural farm in Dwikozy the economic effectiveness of the chemical protection of annual seedlings of potted chrysanthemums was examined in the plastic tunnel. Integrated Pest Management used in chrysanthemum cultivation was based on pesticides recommended by the Institute of Plant Protection – National Research Institute in Poznan, for years 2012–2015. In the study, the real costs of plant protection and the economic effectiveness of these treatments were expressed as approximate profitability indexes E1 and E2. The studies showed that the real costs of the protection of chrysanthemum treatment ranged be-tween 0.421–1.323PLN /m2, depending on the year. The approximate profitability index of plant protection (E2) ranged from 0.97% to 2.64% of the yield. The economic effectiveness of chemical protection of potted chrysanthemums depends on the type of pesticide used, which has a direct effect on the value of real costs.