Lactation boosts reproductive costs by depleting maternal condition and delaying subsequent conception. However, some evidence suggests that giraffes (Giraffa camelopardalis) have evolved a mechanism to minimise the time allocated to suckling-induced suppression of ovulation. Here, we show for the first time that wild giraffe cows are impregnated while nursing a young calf. We suggest that a trio of traits (non-seasonal breeding, slow embryonic development and rapid calf growth) have promoted this unusual and flexible female reproductive strategy.