In this contribution we have described basic properties of piecewise-linear (polyhedral) Lyapunov functions in the control of systems with parametric uncertainties and unknown but bounded disturbances. We have shown some numerical procedures for their synthesis and we have presented some applications. It is important to remark that using this kind of functions may require a nontrivial computational effort due to the complexity of their representation. This problem is important, but it may be considered not very crucial if we take into account the modern computer technology.