Objective(s): According to the unique properties of magnetic nanoparticles, their usages in medicine and industry have increased in the last decade. Due to the vital role of liver in the body, the accumulation of CoFe2O4 and CoFe2O4@DMSA was studied. Materials and Methods:The nanoparticles were synthesized by co-precipitation method and were coated with DMSA. The techniques XRD, TEM, DLS, FTIR, AGFM and UV-Visible spectroscopy were used to characterize the nanoparticles. Nanoparticles were injected intraperitoneally in rat and blood samples were collected from the rats’ heart, at 15 and 30 day post injection. The liver of each rat was removed and kept frozen at -70 oC. Results:The size of the pure cobalt ferrite and DMSA coated cobalt ferrite nanoparticles were about 10 nm and 12 nm, respectively. The saturation magnetization of CoFe2O4 and CoFe2O4@DMSA nanoparticles were 44.8 and 33 emu/g, respectively. Statistical analysis of the results indicated that cobalt ferrite nanoparticles were accumulated in liver in all groups. Conclusion: The accumulation of nanoparticles in liver was significantly higher than those of the control group and the level of liver iron accumulation was significantly lower after 30 days of injection in comparison with 15 days post injection in all groups.