In this study, graphene oxide-iron oxide-polypyrrole (GO-Fe3O4-PPy) ternary nanocomposites having high photothermal activity and stability are synthesized and analyzed using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and magnetic hysteresis measurement (VSM). The effect of power density (1.5-2.5 W cm(-2)), concentration (0.01-0.2 mg mL(-1)), and component composition of nanocomposites on the photothermal properties in the near-infrared (NIR) region (808 nm) is examined. The results show that superparamagnetic GO-Fe3O4-PPy ternary nanocomposite exhibits excellent photothermal performance. The temperature reaches to 55.5, 72.3, and 83.1 degrees C under the irradiation of the 808 nm NIR laser at 1.5, 2.0(-), and 2.5 W cm(-2) of power density for 10 min at 0.1 mg mL(-1) photothermal therapy (PTT) agent, respectively, and moreover it has excellent photothermal stability. In summary, it is concluded that synthesized nanocomposites potentially may be used in simultaneous magnetic field-guided treatments. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48837.