Ovulation, fertilization and both normal and arrested embryonic developments in scorpions, are reviewed and discussed. The importance of all three aspects in scorpion reproduction is discussed from both an evolutionary and an ecological outlook. The number of embryos varies within and among scorpion species and is not related to the female's mass prior to parturition. There is a certain loss in embryo numbers and not all of them will become juveniles. The significance of this loss is discussed, and future avenues of research are suggested.