To date, the search for creating stable ferrofluids with excellent properties for biomedical application is one of the challenging scientific and practical investigations. In this study, novel Fe 3 O 4 /Ag nanohybrid ferrofluids from iron sand were synthesized using a double-layer method. The Fe 3 O 4 /Ag nanocomposites exhibited stable crystallite sizes of 11.8 12.1 nm and 36.8-37.2 nm for Fe 3 O 4 and Ag, respectively. The lattice parameters of the spinel structure Fe 3 O 4 and face-centered cubic Ag were respectively 8.344 Å and 4.091 Å. With increasing Ag amount, the crystallite phase of Ag in the nanocomposites increased from 40.2% to 77.2%. The XPS results confirmed that Fe 3 O 4 /Ag nanocomposites were successfully prepared, where Fe 3 O 4 mixed well with Ag via strong ionic bonding. The FTIR results confirmed the presence of Fe 3 O 4 /Ag, oleic acid, and dimethyl sulfoxide as the filler, first layer, and second layer, respectively. The as-prepared ferrofluids exhibited superparamagnetic behavior, where the saturation magnetization decreased with increasing Ag content. The Fe 3 O 4 /Ag nanohybrid ferrofluids exhibited excellent antimicrobial performance against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Candida albicans. More importantly, the Fe 3 O 4 /Ag nanohybrid ferrofluids decreased the progression of liver fibrosisrelated inflammation and fibrogenic activity on hepatic stellate cells.