Blood samples were collected after mating from four female one-humped camels every 10 min for 9-12 h. Luteinizing hormone (LH) was quantified in plasma by radioimmunoassay using antibovine LH. Of the seven observed matings, five were followed by a release of LH, and three by an ovulation (indicated by a subsequent secretion of progesterone). LH levels at the time of mating ranged from 0.7 to 3 ng/ml. When an LH response occurred, the levels increased 1 h after mating and reached a maximum in 2-3 h (ranging from 2.9 to 19.1 ng/ml). A decrease in LH was observed starting 6 h after mating and lasting for 6 h. These results are in agreement with a coitus-induced mechanism of ovulation in the one-humped camel (Camelus dromedarius). They confirm and extend the observations reported in the bactrian camel (Camelus bactrianus).