Studies have been carried out on the simultaneous determination of 8 phthalates, i. e. di-ethyl phthalate (DEP) , di-propyl phthalate (DPP) , di-isobutyl phthalate (DIBP) , dibutyl phthalate (DBP) , benzyl butyl phthalate ( BBP) , di-cyclohexyl phthalate (DCHP) , di-(2-ethylhexyl) phthalate (DEHP), di-octyl phthalate (DOP) and 4 parabens, i. e. methylparaben (MPB), ethylparaben (EPB), propyl paraben (PPB), and butyl paraben (BPB) by gas chromatography in combination with mass spectrometry (GC/MS) in electron ionisation mode (EI) with selected-ion monitoring (SIM) acquisition method. The phthalates and parabens in 15 cosmetic products, including hair sprays, perfumes, deodorants, cream, lotion, etc. were determined. The determination of the samples were performed after sonication-assisted extraction with methanol, cleaned up with an LC-C18 column (3 mL) and analyzed by GC/MS method. The base peak (m/z 149) of the phthalates and the base peak (m/z 121) of the parabens were selected for the screening studies. The characteristic ions, m/z 121, 149, 177, 222 for DEP; m/z 149, 191, 209 for DPP; m/z 57, 149, 223 for DIBP; m/z 104, 149 for DBP; m/z 91, 132, 149, 206 for BBP; m/z 55, 149, 167 for DCHP; m/z 113, 149, 167, 279 for DEHP; m/z 149, 279 for DOP; m/z 65, 93, 121, 152 for MPB; m/z 93, 121, 138, 166 for EPB; m/z 93, 121, 138, 180 for PPB; and m/z 93, 121, 138, 194 for BPB were chosen for quantitative studies. These techniques are capable to detect phthalates and parabens at the level of 0. 1 -5. 0 microg/kg. Overall recoveries were 80% - 100% with relative standard deviations (RSDs) less than 10%. Only one of the 15 examined samples was free from phthalates and parabens. The rest 14 samples were found to contain at least 3 or more of these phthalates and/or parabens. The predominant phthalates detected in the studied samples were MPB, PPB, DPP, DCHP and DEHP. The residue levels were at 1. 42 -4 278 mg/kg.