The whiptail wallaby reaches sexual maturity between 18 and 24 months for females and at over 2 years for males.

Macropus parryi gives birth to a single young, frequently around January, after a gestation period of approximately 34-38 days. This is followed by 37 weeks of nursing, during which the young wallaby suckles on one of four teats in its mother's pouch. Unlike some other species of wallaby, in which a mother forceably removes her young when the time is right, the young Macropus parryi leaves the protective pouch on its own. Newborn young have a mass of about one gram (less than 0.03 ounces.)

Average gestation period: 36 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)

Sex: male: 883 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 745 days.