As with other cats, the male lion's penis has spines which point backwards. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which may cause ovulation. A lioness may mate with more than one male when she is in heat; during a mating bout, which could last several days, the couple copulates twenty to forty times a day and are likely to forgo eating.

Lions reproduce very well in captivity. During a mating bout, a couple may copulate twenty to forty times a day for several days; the ruff of the female is clearly visible. The average gestation period is around 110 days, the female giving birth to a litter of one to four cubs in a secluded den (which may be a thicket, a reed-bed, a cave or some other sheltered area) usually away from the rest of the pride.