Vitellogenesis, the production of vitellin (major yolk protein), is controlled in decapod crustaceans by several hormones. With increasing efforts world-wide to successfully culture economically important crustaceans, such as shrimp, there is growing interest in attaining a better understanding of the process of vitellogenesis and its hormonal control in these organisms, the ultimate aim being to increase production of cultured species. This review mainly treats recent advances in identification of the sites of production of vitellin and its precursor, vitellogenin, such as the hepatopancreas and the ovaries, the chemistry and synthesis of vitellogenin and vitellin, enzyme-linked immunosorbent assays  (ELISA)  for vitellin, and the hormones, such as methyl farnesoate and  the  gonad-inhibiting hormone, that  regulate vitellogenesis. In addition, the roles of the identified neurotransmitters serotonin (5-hydroxytryptamine) and dopamine in controlling release of at least some of these reproductive hormones and the possible use of the degree of ovarian maturation as a biomarker of exposure to endocrine-disrupting chemicals in the environment are discussed.