We consider networks of input-to-state dynamically stable (ISDS) systems and use a small-gain condition to assure the ISDS property for their interconnection. Under this small-gain condition we provide a construction of an ISDS Lyapunov function including explicit derivation of corresponding rates and gains for the whole interconnection. Key words: Nonlinear systems, input-to-state dynamical stability, interconnected systems, ISDS Lyapunov function, small-gain condition