Okapi's participate in sexual reproduction like most mammals do, with a male and female coming together to combine their DNA. Okapi are very solitary creatures and most of their interactions with each other involve coming together to mate. The male will usually stray from his own territory and enter the home range of a female to determine whether or not she's willing to mate, but it can be hard for them to find each other in the dense forest undergrowth so the male will call to the female to signal his presence and intention.

If mating is successful the female will be pregnant for about 440 days (14 months) before giving birth to a single calf. In the wild this is when the mother and calf are largely separate, the mother will leave the calf hidden in a nest of some kind and return periodically for feeding. This it thought to help in hiding the calf from would-be predators, the less the mother visits the less likely it is for a predator to find the calf by sense of smell or by tracking her movements.

The okapi calf will grow quite quickly, it will begin to take in solid foods at about its 3rd week and signs of rumination can be seen by the 6th week. By the time 6 months have passed the calf will have been weaned. Only after a year has passed will their ossicones begin to develop and take shape, and although they may reach sexual maturity after a year or two depending on their sex, they won't reach adult size until they're about 3 years old.