The study was conducted to evaluate the applicability of ultra high-performance liquid chromatography - tandem mass spectrometry method (UHPLC-MS/MS), establish the MS/MS detection parameters and determine the validation characteristics for the analysis of residual content of avermectins in milk. The UHPLC-MS/MS method has proved to be accurate, practical and universal. This was confirmed by Decision limit (CCα) data: abamectin - 12.56 μg/kg, doramectin - 17.74 μg/kg, eprinomectin - 24.02 μg/kg, ivermectin - 12.53 μg/kg, moxidectin - 44.69 μg/kg, recovery is 88.7-110%. The data obtained for assessing the suitability, accuracy and reproducibility of the results meet the requirements of the European Directive (2002/657/EC). The efficient ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method that was developed and adopted for routine use by the laboratories of veterinary medicine, allows to detect residual quantities of 5 avermectins used in animal breeding for the prevention of helminthiases in food products including milk.