BACKGROUND: We report unusual and/or significant complications encountered during and after the Nuss Procedure for pectus excavatum. METHODS: This was a retrospective review that was approved by the institutional review board, with parental consent. RESULTS: Seven patients had unique and/or significant complications as follows: (1) laceration of an internal mammary artery during bar placement requiring emergent minithoracotomy; (2) hemopericardium 10 weeks postoperatively after blunt chest trauma requiring exploration of the pericardium and clot evacuation; (3) almost complete recurrence of the pectus excavatum deformity immediately after bar removal; (4 and 5) immediate/early postoperative bar displacement requiring re-operation and placement of 2 bars each; and (6 and 7) almost complete neo-ossification of the Nuss bar, making removal challenging. CONCLUSIONS: The Nuss procedure has met with near-universal acceptance. Complications are just being reported. We describe 7 events to add to the evolving literature as the entire pediatric surgery community participates in the initial learning curve.