Magnetic nanocomposites (Fe3O4-MPTMS-PLGA) were synthesized by single oil emulsion method and characterized by transmission electron microscopy (TEM), X-Ray diffraction (XRD), and vibrating sample magnetometer (VSM). Particle size of nanocomposites was between 117 nm and 246 nm. High performance liquid chromatography (HPLC) was used to investigate drug loading (paclitaxel, PTX) and release from Fe3O4-MPTMS-PLGA-PTX nanocomposites. The percentages of drug loading and encapsulation efficiency onto nanocomposites were found as 7.35 and 68.58, respectively. Cytotoxities of free anticancer drug and anticancer drug-loaded nanocomposites were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. In vitro cell culture studies indicated that Fe3O4-MPTMS-PLGA-PTX had significant toxicity on MG-63 cancer cells.