BACKGROUND: The relationship between branch-duct intraductal papillary mucinous neoplasms (IPMNs) and malignancy remains controversial and difficult to assess. METHODS: Between January 1, 1999 and January 1, 2013, we identified 84 patients with IPMN who underwent resection. RESULTS: Preoperatively, 55 patients underwent endoscopic ultrasounds and 58 underwent biopsy. Only 7 lesions were specified preoperatively as branch-duct, which inconsistently correlated with the surgical specimen. Of the 82 patients where the duct was specified, there were 33 malignant lesions. There was no correlation between branch-duct origin and invasive carcinoma. Malignant tumor size did not significantly differ by the duct of origin. Of the 28 patients with invasive carcinoma, branch-duct lesions were significantly associated with the presence of positive lymph nodes, perineural invasion, and lymphovascular invasion. CONCLUSIONS: Our study supports the resection criteria for branch-duct IPMN based on size and symptoms. However, it also questions the reliability of our preoperative testing to rule out malignant branch-duct IPMN lesions.