The growth and development of the endangered Mahogany Glider (Petaurus gracilis) was monitored in a captive population at Burleigh Heads, Queensland, Australia. Video surveillance confirmed that the gestation period for this species was 16 days. Morphometric data and developmental milestones were recorded from 10 Mahogany Gliders from birth to weaning. Growth curves were developed for head length, ulna length, tail length, and body weight. Weekly inspections of female pouches revealed the young's eyelid margins were visible by Day 21, the first hair erupted on the bridge of the nose at Day 30, pigmentation of the body developed at Day 63, and they started detaching from the teat intermittently, and the body was covered in short fur by Day 70. The young were left in the nest alone from Days 84 to 87, their eyes opened between Days 84 and 94, and there was a rapid increase in length and density of fur from Day 98 onwards. At Days 101 to 105 of age the young left the nest box with its mother as back young. Weaning occurred from 184 to 187 days. Typically, the reproductive rate was two young per annum per pair, but one pair produced five young in 19 months. Females produced young from 12 months to 7 years of age, males up to 9.4 years of age. The average longevity of Mahogany Gliders in the studbook in 2018 was 11.6 years. This study provides data on the reproductive biology of the Mahogany Glider that will assist in its captive breeding, management, and conservation.