Oocyte competence is acquired throughout oogenesis, via the interaction with somatic cells. The ability to reinitiate the meiotic process and undergo preimplantation development is progressively determined during the antral phase. It is well-known that these changes involve the nuclear and cytoplasmic compartments, respectively, but the underlying cellular and molecular mechanisms are still poorly understood. The oocyte undergoes a progressive series of morphological modifications as it grows and proceeds through the different stages of development. These structural rearrangements facilitate the increasing energy and nucleic acid synthesis requirements of the developing oocyte and are a prerequisite to the oocytes achieving meiotic and embryo developmental competence. The complexity of the orchestration of the events that control oocyte growth and ultimate acquisition of developmental competence is under continuous investigation. The present review describes some of the findings to date.