Background: Crohn's disease is often poorly responsive to conventional therapy with corticosteroids and immunomodulators. A novel chimeric antibody to tumor necrosis factor-⍺, infliximab, has shown utility in the treatment of refractory Crohn's disease in adults. Purpose: To evaluate the efficacy of open-label administration of infliximab in children and adolescents with active intestinal Crohn's disease. Methods: Chart review of the experience with 19 subjects (mean age 14.4 years, range 9 to 19 years) receiving 1 to 3 infusions of infliximab (5 mg/kg/dose) over a 12-week period for corticosteroid-resistant disease (n = 7) or corticosteroid dependence (n = 12). Disease activity was monitored by physician global assessment and the Pediatric Crohn's Disease Activity Index. Results: Significant initial improvement (first 4 weeks after infusion) was noted in all subjects, with Pediatric Crohn's Disease Activity Index values decreasing significantly (mean ± SD, 42.1 ± 13.7 to 10.0 ± 5.6, P < .0001). Over the subsequent 8-week period, 8 of 19 treated subjects had worsening of symptoms, although none deteriorated to severe activity. The mean Pediatric Crohn's Disease Activity Index at 12 weeks was 26.8 ± 16.4. The mean daily prednisone dosages at baseline, 4 weeks, and 12 weeks were 28 ± 14 mg, 20 ± 12 mg, and 8 ± 12 mg, respectively (P < .01). Adverse effects were noted in 3 patients during infusion (dyspnea, rash) and were self-limited. Conclusions: Infliximab is associated with short-term clinical improvement in children and adolescents with severe Crohn's disease. The rapid return of disease activity in some patients suggests that additional dosing strategies may be required. Long-term safety necessitates close monitoring. (J Pediatr 2000;137:192-6)