Objective: To assess long-term outcomes after ileal pouch-anal anastomosis (IPAA) in Crohns disease (CD). Summary Background Data:: Although considered the procedure of choice in ulcerative colitis, performance of ileal pouch-anal anastomosis (IPAA) is controversial in CD. Methods: CD patients were identified from a prospectively maintained IPAA database. Time-to-diagnosis and pouch retention rates were analyzed using Kaplan-Meier curves. Demographic, clinical, and pathologic factors associated with pouch retention were evaluated with log-rank test and Cox proportional hazards model. Results: Two hundred and four CD patients (108 female, median age 33 years, and median follow-up 7.4 years) with primary IPAA were included. CD diagnosis was before IPAA (intentional) in 20(10%), from postoperative histopathology (incidental) in 97(47%) or made in a delayed fashion at median 36 months after IPAA in 87(43%). Overall 10-year pouch retention was 71%. On multivariate analysis, pouch loss was associated with delayed diagnosis (P = 0.03, hazard ratio [HR] 2.6 (95% confidence interval [CI] 1.1-6.5)), pouch-vaginal fistula (P = 0.01, HR 2.8 (95% CI 1.3-6.4)), and pelvic sepsis (P = 0.0001, HR 9.7(95% CI 3.4-27.3)). Patients with retained IPAA at follow-up had near-perfect/perfect continence (72%), rare/no urgency (68%) with median daily bowel movements 7 (range 2-20). Median overall quality of life, quality of health, level of energy, and happiness with surgery were 9, 9, 8, and 10 of 10, respectively. Conclusions: For CD patients with IPAA, when the diagnosis is established preoperatively or immediately following surgery, pouch loss rates are low and functional results are favorable. Outcomes in patients with delayed diagnosis are worse but half retain their pouch at 10 years with good functional outcomes.