This paper presents a design procedure for two-dimensional (2-D) zero-phase IIR notch filters based on the state-space representation of 2-D frequency transformation in the Fornasini-Marchesini second (FM II) model. It will be shown, via several typical image processing examples, that 2-D zero-phase IIR notch filters can be designed more flexibly by utilizing the state-space representation of the 2-D frequency transformation proposed by the authors recently, so that the distortion caused by nonlinear phase of the filter can be avoided and thus the designed filters perform better than the corresponding frequency domain filtering methods.