A method for the determination of 300 pesticides in tea samples and plant infusions has been developed in this paper by modified QuEChERS method and gas chromatographic mass spectrometry (GC-MS/MS). The developed method, which was characterized by fast speed analysis, simplicity and economy despite a large number of analyzed pesticides, was confirmed in accordance with instructions from SANTE/11813/2017 and applied in routine work. For this purpose, GC and MS/MS parameters were optimized at the beginning and afterward emphasis being given to the modification of the original QuEChERS method, designed for samples with more than 75 % of water content. The total analysis runtime of developed method is 28 minutes with injection volume of 0.6 μL. The developed method is validated. Matrix-matched calibration curves were used for accurate quantification (ranging from 10 μg/kg to 250 μg/kg) to compensate the matrix effect. Limits of quantification (LOQs) are in range between 0.06 μg/kg and 135 μg/kg, and for most pesticides, LOQ is below the regulatory maximum residue level. Most of recoveries for 10 μg/kg range from 70 to 120 % which indicates satisfactory method accuracy. The validated method was applied to analysis of commercial tea samples and herbal infusions and the presence of chlorpyrifos, DEET, tebuconazole, terbuthylazine, piperonyl butoxide, biphenyls, pendimethalins, pirimiphos-methyl and 4,4'-DDE was found in more than 100 samples of total 1466 analyzed real samples. For these most commonly proven pesticides, calculation of human health risk assessment was calculated.