Multifunctional nanocomposites represent a new class of multiphase materials containing dispersion of nanosized filler materials such as nanoparticles within the polymer matrices. In this study, a polyaniline@polyxanthonetriazole@Fe 3 O 4 (PANI@PXT@Fe 3 O 4 ) trilayered nanocomposite was synthesized successfully through emulsion polymerization of PANI in the presence of a dilayered magnetic polyxanthone triazole (PXT@Fe 3 O 4 ) composite. Nuclear magnetic resonance, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and vibrating sample magnetometry were used for characterization of synthesized materials. The antioxidant and antibacterial activities of PANI, PXT, PXT@Fe 3 O 4 , and PANI@PXT@Fe 3 O 4 trilayered nanocomposite were investigated by 2,2-diphenyl-1-picryl-hydrazyl free radical (DPPH • ) and inhibition zone assays, respectively. Summing up, the results showed a synergic effect on thermal stability, antioxidant, and antibacterial activities of the PANI@PXT@Fe 3 O 4 trilayered nanocomposite. Consequently, the developed PANI@PXT@Fe 3 O 4 trilayered nanocomposite is a suitable candidate for biological applications. C