© 2020 The Royal Society of Chemistry.This study presents a dispersive solid-phase extraction (DSPE) method based on fatty acid (stearic acid) functionalized magnetite nanoparticles (SACMNP) for the extraction and preconcentration of ultra-trace lead from aqueous samples for sensitive determination by a hydride generation-flame atomic absorption spectrometry (HG-FAAS) system. To achieve that, magnetite nanoparticles (MNPs) were synthesized and coated with stearic acid in order to obtain a higher surface area and increased selectivity. The optimum values obtained from the combination of HG-FAAS and SACMNP-DSPE were determined through the one-variable-at-a-time optimization technique. The following results were calculated under the optimum conditions; a limit of detection (LOD) value of 0.16 μg L-1 and a limit of quantification (LOQ) value of 0.52 μg L-1. Standard and certified reference materials (SRM and CRM) were used to verify the developed method's accuracy and the results obtained (SRM: 99.6 ± 5.8%, CRM: 101.8 ± 4.9%) indicated high quantification accuracy.