In this study, a mixed hemimicelle solid-phase extraction method based on Fe3 O4 nanoparticles coated with sodium dodecyl sulfate was applied for the preconcentration and fast isolation of six fluoroquinolones in environmental water samples before high-performance liquid chromatography determination. The main factors affecting the extraction efficiency of the analytes, such as amount of surfactant, amount of Fe3 O4 nanoparticles, extraction time, sample volume, sample pH, ionic strength, and desorption conditions, were investigated and optimized. The method has detection limits from 0.05 to 0.1 ng/mL and good linearity (r ≥ 09948) in the range 0.1-200 ng/mL depending on the fluoroquinolone. The enrichment factor is ∼200. The recoveries (at spiked levels of 1, 5, and 50 ng/mL) are in the range of 79-120%.