The diversity of the clinical features of HandSchuller-Christian disease is well recognized. Although it is a disorder affecting chiefly young children, its occurrence in the first year of life is rare.The two cases presented here indicate that the form of the disease found in infants tends to be more rapid in its course and the lesions more widespread than in older children. At October 25, 1944, at the age of 9 months. Her parents and an elder brother and sister were quite well, and the pregnancy and labour had been normal. There was some difficulty with feeding until the age of 6 weeks when breast feeding was replaced by a cow's milk mixture. At the age of 3 weeks her mother noticed that there were three red spots on the roof of the mouth. The significance of this observation is not known and no further mention of it is made in the case notes.At the age of 4 months (five months before admission) the right side of the face became swollen. At first the child was thought to be suffering from mumps but shortly afterwards she was admitted to a hospital near her home, and the cervical lymph nodes were incised. The only material obtained at the operation was said to be congealed blood. The lymph nodes on both sides of the neck increased in size and the child's general condition deteriorated rapidly.On admission she was extremely ill, pale, dyspnoeic and cyanosed. The temperature was 960 F., the pulse 154 per minute and respirations 86 per minute. Large subcutaneous masses were found on both sides of the neck. They were firm, smooth, and fixed to the deep structures. The percussion note at both posterior lung bases was impaired and coarse crepitations were heard in all areas. The abdomen was very distended, the liver just palpable, and the spleen was firm and enlarged to three fingersbreadths (2 in.) below the costal margin.