In the present study, a chemical route was employed to synthesize graphene oxide (GO)-reduced graphene oxide (rGO)-Ag nanoparticle (AgNP) composites from graphite and AgNO3 using vitainin C as reducing agent. Powder X-ray diffraction pattern and field emission scanning electron microscope images revealed that the AgNP were uniformly distributed on the surface of GO and rGO nanosheets. For the first time, the cytotoxicity of GO, rGO, AgNP, GO-AgNP and rGO-AgNP composites were examined against human lung cancer A549 cells using MIT assay and reported quantitatively. The rGO-AgNP showed significant cytotoxicity activity with an IC50 value of 30 mu g/mL towards A549 cells which is higher than that of GO (180 mu g/mL), rGO (160 mu g/mL) and GO-AgNP (100 mu g/mL). Compared to AgNP (6 mu g/mL), rGO-AgNP shows partial agglomeration of AgNP on rGO sheets, which reduces the interaction between rGO-AgNP and A549 cells leading to lesser anticancer activity than AgNP. The interaction between rGO and AgNP leads to increase in the material biocompatibility, reducing the toxicity and corrosive characteristic. (C) 2017 Elsevier Inc. All rights reserved.