L'Hoest's monkey breeds seasonally, depending on area. After about a 5 month gestation, a single young will be born. The mother gives birth typically at night and where ever she happens to be at the time. Birth usually occurs at the end of the dry season, which allows lactation when rainfall is highest. After a few months nursing becomes less frequent, but will continue for about two years when there is another birth. In captivity they have been known to live for more than 30 yrs.