The concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the serum of the Bactrian camel (Camelus bactrianus) throughout pregnancy were analysed by radioimmunoassay. The samples were withdrawn at intervals of half a month. The serum LH concentrations varied significantly between 2.2+/-0.9 and 20.3+/-18.8 ng/ml during the pregnancy, with the highest value on the day of artificial insemination, which indicated that a preovulatory LH peak appeared. Thereafter, the LH concentration tended to fall, reaching a fairly constant low level by the eighth month of pregnancy. The serum FSH concentrations varied between 7.0+/-0.2 and 28.9+/-0.4 ng/ml during gestation, with the peak value being reached at 4.5 months, followed by a marked drop to 7.0+/-0.2 ng/ml at 7.5 months.