Investigations on the self-assembly of block copolymers in solution have in some way a. less well-studied history than the study of their phase separation in the solid state, and many aspects are yet not completely understood. Here we focus on the behavior of a specific class of copolymers, namely semicrystalline block copolymers, capable of forming cylindrical aggregates in a solvent selective for the non-crystalline, complementary block. A common model of micellization is proposed, in principle applicable to most of these copolymeric systems.