Beneficial species of predators and parasitoids play an important role in sustainable pest control. Toxicity evaluation of insecticides against the natural enemies of the pests is very important in the selection of a product intended for application within the Integrated Pest Management (IPM). The effectiveness of beneficial species as biological control agents may be compromised by side effects caused by insecticides. Tests were conducted under laboratory conditions to determine the toxicity of 18 insecticides against the beneficial species Encarsia formosa Gahan, Macrolophus pygmaeus Rambur and Amblyseius cucumeris Oudeman. Plant protection products Rapax (i.e. Bacillus thuringiensis subsp. kurstaki strain EG 2348) 0.1%, Dipel 2X (i.e. Bacillus thuringiensis var. kurstaki strain ABTS) 0.1%, Naturalis (i.e. Beauveria bassiana strain ATCC 74040) 0.1%–0.15%, Helicovex (i.e. Helicoverpa armigera nucleopolyhedro virus Hear NVP, DSMZ–BV0003) 0.02%, Neem Azal T/S (i.e. azadirachtin) 0.3% and Limocide (i.e. orange oil) 0.4% were slightly toxic (toxicity up to 37%) to the tested bioagents. They can be successfully applied in integrated plant protection systems. Toxic to highly toxic were the following insecticides: Koragen 20 SC 0.02%, Voliam Targo 063 SK 0.08%, Ampligo 150 ZK 0.04%, Closer 120 SC 0.04%, Confidor Energy OD 0.08%, Vaztak new 100 EC 0.03%. These insecticides should be avoided when introducing bioagents into greenhouses. Keywords: Encarsiaformosa, Macrolophuspygmaeus, Amblyseius cucumeris, toxicity, plant protection products