This paper presents a symbolic and recursive calculation of the stiffness and mass matrices of parallel robots. In order to reduce the computational time required for simulating the elastodynamic behavior of robots, it is necessary to minimize the number of operators in the symbolic model expression. Some algorithms have been proposed for the rigid case or for parallel robots with lumped springs. In this paper, we extend the previous works to parallel robots with distributed flexibil-ities. The proposed algorithm, that takes advantage of recursive calculations for the computation of the Jacobian matrices defining the kinematic constraints, is used to compute the natural frequencies of a robot developed at IRCCyN: the NaVARo.