Changes in body mass, length of forearm, and length of total epiphyseal gaps of young Formosan leaf-nosed bats (Hipposideros terasensis) were monitored by marking and recapturing at a maternity colony in central Taiwan. Length of forearm and body mass of 1-day-old neonates averaged 43.3 mm ± 2.7 SD and 15.9 g ± 3.3 SD, respectively. Increase in forearm length and body mass was fastest in the 1st week after birth, but rate of increase decreased thereafter. Length of total epiphyseal gap increased to its maximum size at about 10 days after birth and subsequently decreased linearly. Growth constants derived from the logistic growth model were 0.096 and 0.114 for the increase in length of forearm and body mass, respectively. Age of H. terasensis between 1 and 44 days can be estimated either by length of forearm when forearm length is ≤91 mm or by length of total epiphyseal gap when forearm length is >91 mm. Subsequent monitoring suggested that males of H. terasensis are capable of reaching sexual maturity in their 1st year and females in their 2nd year. When compared with other bats, growth rate of H. terasensis was faster than that of many tropical species but slower than that of most temperate species.