The period of gestation of the volcano rabbit (Romerolagus diazi) was measured. Females were cohabited within one hour after confirmation of coitus or were separated from the males after cohabiting overnight. In 12 females which gave birth 20 times in total, the gestation period was 39 days in 35%, 40 days in 50% and 41 days in 15%; 85% of animals showed a gestation period of 39 or 40 days.