Objective: To develop a gold nanoparticles complex conjugated with interferon-gamma(IFN-g) and methionine along with application of hyperthermia using near-infrared laser beams for the treatment of cancer cells.Methods: Gold nanorods(10 nm) were conjugated with IFN-g and methionine using carbodiimide family and characterized after purification by dialysis bags. Breast cancer cells were cultured and incubated with gold nanorods at different concentrations followed by irradiation with near-infrared laser beam. Samples were then evaluated for their viability in order to determine the effect of treatment and variables by MTT assy.Results: Zetasizer results confirmed the conjugation of gold nanorods with methionine and IFN-g. The median percentage of cell viability in 0.30 mg/m L concentration of gold nanorods was 82%. The cell viability reached to 85% at the same concentration of gold nanorods, which existed in the assayed complex. The results of MTT assay showed that the 0.60 mg/m L concentration of gold nanoparticles complex was toxic on tumor cells(P < 0.05). After exposure to hyperthermia, the viability of cells at 6 min decreased to77% in 0.30 mg/m L concentration of gold nanorods complex.Conclusions: The size and concentration of gold nanorods was not cytotoxic. However,their presence during irradiation near-infrared laser increased the number of dead cells during the treatment of cells. Objective: To develop a gold nanoparticles complex conjugated with interferon-gamma (IFN-g) and methionine along with application of hyperthermia using near-infrared laser beams for the treatment of cancer cells. Methods: Gold nanorods (10 nm) were conjugated with IFN -g and methionine using carbodiimide family and characterized after purification by dialysis bags. Breast cancer cells were cultured and incubated with gold nanorods at different concentrations followed by irradiation with near-infrared laser beam. Samples were then evaluated as their viability in order to determine the effect of treatment and variables by MTT assy. Results: Zetasizer results confirmed the conjugation of gold nanorods with methionine and IFN-g. The median percentage of cell viability in 0.30 mg / mL concentration of gold nanorods was 82%. The cell viability reached to 85% at the same concentration of gold nanorods, which existed in the assayed complex. The results of MTT assay showed that the the 0.60 mg / m L conce ntration of gold nanoparticles complex was toxic on tumor cells (P <0.05). After exposure to hyperthermia, the viability of cells at 6 min decreased to 77% in 0.30 mg / m L concentration of gold nanorods complex. Conclusions: The size and concentration of However, their presence during irradiation near-infrared laser increased the number of dead cells during the treatment of cells.