This is a summarized review about some aspects of the yolk formation in crustacean. At the beginning of vitellogenesis, the crustacean oocyte is characterized by a large number of vesicles in the cytoplasm. The vesicles have a multiple origin, although the majority develop directly from the rough endoplasmic reticulum and the Golgi complex (endogenous phase of vitellogenesis). In a subsequent phase, a series substances, principally glucoproteins and lipoproteins, are incorporated into the ooplasma by means of micropinocytosis (exogenus phase of vitellogenesis). The result of this process is the formation of one or several types of yolk platelet.