Fourteen specimens of Vaejovis coahuilae Williams 1968 were born in the laboratory and reared in an incubator at a near-constant 27 °C. A single female reached maturity at the 8th instar, as previously hypothesized, but unverified, in this species. Two other specimens reached the 7th instar, but the male died at the molt and the female was not yet mature. Data on the duration and morphometrics of observed instars are provided for all specimens.