BACKGROUND: The objective of this study was to understand the frequency and types of complications, and the associated postoperative outcomes within the first 5 years of practice after hand and upper extremity surgery fellowship. METHODS: This was a retrospective observational study of all patients seen and surgically treated by a single surgeon at a single institution from August 2014 to September 2019. This corresponded to the first 5 years of practice after fellowship. Data collected included patient demographics, perioperative data, complication type, and outcome of the complication (better/same/worse than preoperative status). Complications were classified using the Clavien-Dindo system and a unique, self-derived system. RESULTS: In total, 3301 surgeries were performed during the first 5 years of practice. The overall complication rate was 7.9% (261 complications from 239 patients). The 30-day complication rate was 5.2% (171/3301). Eleven (4.2%) of the 261 complications occurred intraoperatively. The total number of complications significantly declined during the first 5 years of practice as follows: 74, 71, 46, 37, and 33 ( CONCLUSION: The overall surgical complication rate for hand and upper extremity surgery was 7.9%, with a 30-day complication rate of 5.2% (171/3301). The rate of complications after fellowship declined over the first 5 years of independent practice. Superficial infections were the most common complication. More than 90% of patients ultimately improved after addressing the complication. LEVEL OF EVIDENCE: IV.