Tityus stigmurus (Thorell 1876) is one of the most medically important scorpion species in Brazil, but many basic aspects of its life history are unknown. Here the pattern of female reproductive investment was examined, along with development of the 1^st and 2^nd instars and the relationship between 2nd instar mass and molting to the 3^rd instar. Relative to other buthid scorpions, T. stigmurus has a smaller litter (average 10 young) and a shorter 1^st-instar period (average 4 days) and 2^nd-instar period (average 68 days). Neither litter size nor offspring mass showed a relationship to female size. A significant positive correlation was observed between total litter mass and litter size. The minimum mass required for successful molting to the 3^rd instar was 34.0 mg. Overall, female reproductive resources in T. stigmurus appear to be applied to the production of more but not heavier offspring.