Persistent urachal remnants are uncommon congenital anomalies. Unless an umbilical fistula exists, infection may be the first indication of this abnormality. Five children received initial treatment for this problem at the Children's Hospital of Buffalo during a 20-year period, 1964 to 1984, and a sixth was seen secondarily. There were four boys and two girls; their ages ranged from 8 months to 9 years. Lower abdominal mass with fever and local tenderness were the most common presenting signs. Ultrasound was the most accurate study, correctly diagnosing the cyst in both patients so examined. Incision and drainage alone was performed in one patient. The other five were managed with antibiotic therapy and complete excision as the primary procedure. Cultures were obtained in five patients and were positive in four, growing Staphylococcus aureus in three and Escherichia coli in one. Significant genitourinary abnormalities were discovered in four of the five patients evaluated. It is concluded that the previously recommended therapy of incision and drainage followed by delayed resection was developed in the preantibiotic era to minimize the mortality from sepsis and the morbidity from recurrence. Our experience indicates that the use of appropriate antibiotics followed promptly by complete cyst excision as a primary procedure is both possible and safe in most cases. Furthermore, the large number of associated genitourinary abnormalities suggests that a complete work-up for these conditions should be performed.