Facile synthesis of ZnO/GdCoO3 nanocomposites in a two-phase system utilizing Myristica fragrans leaf extracts (MFE) assisted by a high-speed stirring method has been reported. The amine functional group was reported in MFE, confirming the presence of alkaloids. ZnO/GdCoO3 exhibits the combination phase of the typical diffraction peak of both ZnO and GdCoO3. The calculated bandgap value of nanocomposites was found to be 1.99 eV. The particle size of ZnO/GdCoO3 nanocomposites was obtained in the range of 34-58 nm. The photocatalytic activity was evaluated for dyes degradation under visible light illumination. Within 120 min, ZnO/GdCoO3 nano composites can degrade the malachite green (MG) as a model of dye with an efficiency of 92.4%. Importantly, ZnO and GdCoO3 display a synergetic effect in a nanocomposite structure as an efficient photocatalyst for dyes degradation.