The course of Crohn's disease is quite variable in children. To assess the frequency and indications for surgery with current medical therapy, the authors reviewed the cases of 204 children (ages, 0.2 to 18.8 years at diagnosis, median, 12.8 years) who had Crohn's disease treated at a single institution from December 1968 to January 1994, with a median of 3.8 years of follow-up (range, 0.0 to 22.2 years). Ninety-four children (46%) required surgical resection for the following indications: (1) failure of medical therapy with persistent symptoms or growth retardation (n = 44, 47%), (2) intraabdominal abscess or perforation (n = 15, 16%), (3) fistula formation (n = 13, 14%), (4) obstruction (n = 15, 16%), (5) hemorrhage (n = 4, 4%), and (6) appendectomy at exploration for diagnosis (n = 3, 3%). The probability for surgery 3 years after diagnosis is 28.8% and by 5 years is 47.2%. Resections included ileocolectomy (71 children), colectomy (n = 16), small bowel resection (n = 4), and appendectomy (n = 3). Fourteen fistulas in 13 children required surgical intervention (7 enteroenteral, 3 enterovesical, 2 enterovaginal, and 2 enterocutaneous). The median duration from diagnosis to surgery for the fistulas was 2.6 years (range 0.1 to 9.8 years). Forty patients experienced recurring disease after resection during follow-up with a median of 1.8 years (range 0.4 to 18.1 years). The authors found that the course of the disease was unpredictable, with some children requiring early surgical intervention and others continuing with medical therapy for years.