A circuit realization is presented for two-dimensional (2-D) lattice discrete filters. The number of delay elements is minimal. Based on this circuit realization, the corresponding state space realization is derived. The matrices A, b, c′, and the scalar d of the 2-D state space model are presented in generalized form. The dimension of the 2-D state space vector is minimal, and the corresponding transfer function is characterized by the all-pass property.