Two series of linear SBV and BSV triblock copolymers have been prepared where S is polystyrene, B is polybutadiene and V is poly(2-vinylpyridine). While the ratio between the weight fractions of S and B was kept constant, the weight fraction of V was varied within each series. Morphological characterization was carried out by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). While BSV triblock copolymers show lamellar morphologies independent of the V content, the SBV triblock copolymers show different core-shell morphologies and a lamellar morphology as a function of the V content.