This review of the subject is based on 61 patients seen during a 10-year period at the Children's Medical Center in Boston. Attention is concentrated on 20 patients who had survived from 7 months to 13 years. The intestinal obstruction from viscid meconium was relieved by surgery in 15 patients and by medical means in 5. Details of the immediate surgical and medical treatment are given. The subsequent treatment is along generally acceptable lines. The ultimate prognosis depended upon the severity of the pulmonary lesion which usually developed during the first few months of life. The appearance of this manifestation could not be prevented by careful attention to the nutrition, pancreatic enzyme substitution therapy or prophylactic antibiotics. The course of patients surviving meconium ileus does not differ materially from those patients whose first manifestations of the disease appear in the first months of life without antecedent meconium ileus. The literature concerning meconium ileus is thoroughly reviewed.