Chlorpyrifos is one of the most commonly used organophosphorous pesticides. Its toxicity is due to the ability to inhibit key enzymes for the operation of the organisms, thus causing neurological damage. Some microorganisms, such as bacteria and yeasts, show the ability to degrade chlorpyrifos, which is believed to be due to the secretion of specific enzymes such as alkaline phosphatase. The aim of the present work was threefold: 1. to investigate the ability of six strains of lactic acid bacteria to grow in the presence of different concentrations of chlorpyrifos; 2. to evaluate their secretion of alkaline phosphatases by a colorimetric method applying ρ–nitrophenyl phosphate as substrate; and 3. to quantify the degradation of the pesticide by a mass spectrometry coupled to gas chromatography technique. The degradation rate was calculated by comparison with a control that had only pesticide in the same initial concentration used in tests. All tested strains were able to grow in chlorpyrifos concentrations up to 500 mg.L-1 and there was no significant difference in alkaline phosphatases secretion, which ranged from 0.0200 to 0.0226 U.mL-1.min-1.All tested strains were able to efficiently degrade the pesticide, with minimal degradation of 80.3%.After 48 hours of incubation, the culture medium containing one of the Pediococcus sp. strains presented chlorpyrifos concentration below the detection limit of the analytical method applied, possibly indicating the complete degradation of the pesticide.It is possible that the pesticide is alsoadsorbed by the bacteria, but data from the literature demonstrate that this accounts for only a small proportion of chlorpyrifos removal from the medium by most strains.Therefore, we can conclude that the six strains of lactic acid bacteria tested were able to degrade chlorpyrifosquickly and effectively, even in high concentrations, which proves technically feasible their application for the removal of chlorpyrifos contamination in food products.