In the present study, magnetic nanoparticles (MNPs) were coated with chitosan (CS) polymer to form CS-MNP nanoparticles. The CS-MNP were loaded with an anticancer drug, betulinic acid (BA) to form a BA-CS-MNP nanocomposite. The prepared nanocomposite was characterized using XRD, FTIR, TGA, VSM, SEM, TEM, and zeta potential techniques. The release behavior of the BA from the nanocomposite was investigated at pH 7.4, and the study found that the release of BA followed a pseudo-second-order kinetic model. The potential cytotoxicity of free BA, MNPs, CS-MNP, and the BA-CS-MNP nanocomposite was evaluated using normal mouse fibroblast cells (3T3) and breast cancer cells (MCF-7). BA and the nanocomposite at concentrations in the range 0.781-50 mu g mL(-1) did not affect the viability of normal cells during 72 h of incubation. The BA and BA-CS-MNP nanocomposite exhibited cytotoxicity in MCF-7 cells in a dose-dependent manner with IC50 values of 2 and 3.6 mu g mL(-1), respectively.