Objective: To evaluate the long-term efficacy, safety, and tolerability of aripiprazole in pediatric subjects with bipolar I disorder. Methods: A randomized, double-blind, 30-week, placebo-controlled study of aripiprazole (10 or 30 mg/day) in youths (10–17 years) with bipolar I disorder (manic or mixed) ± psychotic features (n = 296) was performed. After four weeks, acute treatment completers continued receiving ≤26 weeks of double-blind treatment (n = 210). The primary outcome was Young Mania Rating Scale (YMRS) total score change. Results: Of the 210 subjects who entered the 26-week extension phase, 32.4% completed the study (45.3% for aripiprazole 10 mg/day, 31.0% for aripiprazole 30 mg/day, and 18.8% for placebo). Both aripiprazole doses demonstrated significantly (p