This is a study of congenital syphilis in Bogota, Colombia. The immensity of this problem in Colombia can best be realized by considering the author's figures for the frequency. He estimates this at 6 per cent in cases observed in private practice and at 25 per cent in cases observed in clinics. The discussion is taken up in the usual form of statistics, frequency, pathology, laboratory tests, symptoms, prognosis and treatment. All these subjects are presented in a systematic manner. It is of especial interest to one working with these problems to read of the many and varied forms that the symptoms of florid congenital syphilis may take. Of particular interest is the discussion of the relation of rickets and toxic infections such as syphilis. In France, Marfan found 40 per cent of children in the Paris Hospital between the ages of 3 months and 3 years to be rachitic.