This work describes a novel and simple electrochemical sensor for the detection of hydrogen peroxide (H2O2) based on immobilizing ZnFe2O4 nanoparticles on chitosan (CHIT) membrane coated Au electrode. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), Fourier transform infrared (FTIR) spectroscopy and cyclic voltammetry (CV) were used to characterize the sensor. Modification of the Au electrode with ZnFe2O4 MNPs improved the electroactivity of modified electrode (ZnFe2O4 MNPs/Au) towards the H2O2 reduction. Amperometric detection of hydrogen peroxide was carried out at -0.8 V versus SCE reference electrode in phosphate buffer solution at pH 7.5. Under optimal conditions, the electroactivity response of the sensor was proportional to the H2O2 concentration in the ranges of 0.018-2.0 mu M and 2.0-50.0 mu M with excellent correlation coefficients (> 0.99). The detection limit of the method was 2.5 nM, and 95% of steady-state current of the sensor was achieved at lower than 6 s. Electrocatalytic activity, simplicity, excellent stability, repeatability, and reproducibility are some of the advantages of the proposed modified electrode which was successfully applied to determine H2O2 in real samples such as serum.