Photothermal therapy is considered as an alternative to conventional cancer therapy methods, which is a mild practice compared to chemotherapy, radiotherapy, and surgery. The purpose of this study is to synthesize a photosensitizing agent having strong near-infrared (NIR) ((similar to)808 nm) absorption, low cytotoxicity, magnetic properties, and excellent stability. For this purpose, graphene oxide-iron (II, III) oxide-polyaniline (GO-Fe3O4-PANI) was synthesized for the first time towards photothermal application and characterized by UV-vis, FTIR, XRD, TEM, and VSM analyses. The photothermal performance of the nanocomposite was investigated at various concentrations (0.1, 0.05, 0.025 mg/mL) under 1, 1.5, and 2.5 W/cm(2) laser power density values. Photothermal conversion efficiency values of the samples were calculated by time constant method and a maximum of 65.80% efficiency was obtained (0.1 g/mL concentration at 1.5 W/cm(2) for 5 min). This novel nanocomposite demonstrated superior results among PANI based photosensitizing agents.