A simple and sensitive, solid-phase extraction method for the removal of Citalopram drug from waste water has been developed by using magnetic nanoparticles modified with surfactant sodium dodecyl sulfate. These magnetic nanoparticles have shown great adsorptive tendency towards Citalopram drug. The effect of different parameters influencing the extraction efficiency of this drug were investigated and optimized including the pH, amount of the surfactant, contact time and temperature. The extracts were analyzed by ultraviolet spectrophotometry at 239nm. Under these conditions, the related standard deviation (RSD %) of the method at two concentrations (5 and 50Âµg.mL-1) was in the range of (3.14â€“3.75) % (n = 8). The calibration curve was linear in the range of 2-100 Âµg.mL-1 of Citalopram drug with a correlation coefficient of >0.99.