Five cases of Addison's disease and pregnancy are reported. The author also collected data from the literature on the infants of Addisonian mothers. Comparison with control series revealed that on an average infants born to Addisonian mothers weigh 500 g less and are born 13 days later than corresponding control infants. The low birth weight and the long gestation period are presumably due to the low blood sugar level in Addisonian patients. The course and management of pregnancy in Addison's disease are described, and the following guidance for treatment is suggested. Cortisone therapy is most important, usually in daily doses of 25–50 mg, possibly supplemented by DCA and NaCl. Frequent control of body weight, electrolytes, blood pressure, E. C. G., and blood sugar during pregnancy. Therapeutic abortion is not indicated as a general rule. Delivery should not be induced before term. Spontaneous labour may be awaited for some time past term. In principle, the delivery may take place per vias naturales. The dose of cortisone should be increased, during the days before and after delivery, to about 200 mg daily. During and after delivery intravenous administration of cortisol or blood transfusion may be required. The dose of cortisone may be levelled off to normal within the first week post partum. Hormone therapy of the newborn infant is not indicated.