Organophosphate esters (OPEs) are used as flame retardants and plasticizers in electronics, plastics, textiles, furniture, and building materials. The OPEs have been added to the market to replace the polybrominated diphenyl ethers (PBDEs), which are classified as persistent organic pollutants (POPs) by the Stockholm Convention. However, recent studies have found that some OPEs can cause several problems to human health, such as cancer, endocrine, hormonal and reproductive disorders, among others. The OPEs can be transferred to food by the contact with plasticizers during production, packaging and storage processes. The dairy industry has been growing in recent years, and the presence of OPEs in milk was reported. However, there are few studies that have determined the presence of OPEs in milk. The aim of the present study is to develop an analytical method for the determination of ten OPEs in bovine milk. The method is based on QuEChERS extraction and analysis by gas chromatography coupled to mass spectrometry (GC-MS). The recovery tests were carried out using a whole milk matrix (5 mL) spiked at a concentration of 200 ng mL-1 for the classic QuEChERS, and at 20 ng mL-1 for modified QuEChERS. Evaluated modifications included the use of low temperature partition after extraction, concentration of the extract followed by additional clean-up steps using C18 or HLB cartridges, and the use of C18 associated to PSA sorbent during the dispersive solid phase extraction (d-SPE). Matrix effect was observed when comparing the analytical response obtained for the OPEs in standard solutions (prepared using pure solvent – ethyl acetate) and in standards prepared using a dried milk extract (matrix- matched standard). Thus, for these optimization experiments the recoveries were calculated based on the response factor obtained for the matrix-matched standards (milk extract spiked with OPEs) prepared at a concentration corresponding to a recovery of 100%. Preliminary results obtained with classic QuEChERS showed recoveries within the range from 62% to 116% and relative standard deviation from 3% to 29%, except for the tris (2-ethylhexyl) phosphate (TEHP). Regarding the tests using modified QuEChERS with concentration of the extract, the C18 cartridges showed the best recovery performance, which ranged from 99% to 128%, except for the 2-ethylhexyl diphenyl phosphate (EHDPHP) (381%) and TEHP (51%). The optimization of the d-SPE clean-up using PSA and C18 was also evaluated, including additional sorbent washing steps using dichloromethane, acetonitrile or ethyl acetate. The best results have been obtained with ethyl acetate, with recoveries ranging from 78 to 107% for eight out of the ten evaluated OPEs, with relative standard deviation from 4 to 17%. Therefore, based on these results, the modified QuEChERS method is promising for the determination of OPEs in bovine milk.