The main purpose of this paper is to present a method for determining a parametric solution to the problem of modal-control of controllable and observable linear time-invariant multivariable systems via output-feedback. The approach followed is based, at first, on finding a general set of state-feedback modal controllers, then a subset of it is chosen such that it satisfies the necessary and sufficient conditions for the existance of an output-feedback modal-controller . This approach makes use of the controllable canonical form of the given system. A de$ign algorithm is established and it can be implemented with ease. Then, this algorithm is extended to the case of designing modal dynamic controllers with arbit-rarily fixed poles. Two numerical examples are provided to illustrate the theoritical aspects. The paper consists of two main parts: - the first part describes the design of static modal controllers; - the second part is related to the design of dynamic modal controllers.