Ultrasound-assisted emulsification microextraction (USAEME) and gas chromatography – flame ionization detection (GC-FID) was presented for the extraction and determination of olanzapine in human urine and plasma samples. Chlorobenzene at microliter volume level as an extraction solvent without disperser solvent was used. The main advantages of this method are high speed, high recovery, good repeatability and extraction solvent volume at µL level. The effect of several variables such as type and volume of extraction solvent, ultrasonication time, centrifugation time, salt addition, etc. were evaluated, carefully. In the optimum conditions, the calibration curve was linear in the range of 70-2000 µg L-1 with the detection limit of 20 µg L-1. The relative standard deviation (R.S.D.) for the five replicate measurements of olanzapine was 4.6 %. USAEME combined with GC-FID is a fast, simple and efficient method for the determination of olanzapine in human urine and plasma samples. Manuscript profile