Abstract: A method for determination of N-ethyl perfluorooctanesulfonamide in textiles by GC-MS was proposed. N-ethyl perfluorooctanesulfonamide in samples was extracted with methanol ultrasonically and the extract was concentrated to 5 mL in a rotary evaporator. The DB-5MS column was used for separation, and selected ion monitoring mode was used in the MS measurement. Ions used for qualitative analysis were: m/z 69, 108, 131, 169, 448; ion use for quantitative analysis was m/z 108. Linear relationship was obtained between values of peak area and concentration of N-ethyl perfluorooctanesulfonamide in the range of 0.2-20.0 mg·L-1, with detection limit (3S/N) of 0.69 μg·L-1. Test for recovery was made by standard addition method, giving value of average recovery of 97%.