The stability of an articulately supported cylindrical shell subjected to an external uniform lateral pressure is investigated in a three-dimensional formulation. The investigation is based on a static method for the cases of a ″dead″ and a ″following″ load. Solutions are obtained in exponential series. Likewise, analogous results obtained by means of a refined Timoshenko-type theory are presented. Regions of applicability of the applied theories of stability are pointed out. A comparison is made with the experimental results.