Purpose: Complication rates of open partial nephrectomies (OPN) and minimally invasive partial nephrectomies (MIPN) have largely been reported by single and multi-institutional tertiary care centers. We sought to identify complication rates of these approaches and how they are influenced by trainee involvement utilizing an independent national surgical database. Materials and Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) is a risk-adjusted data collection analyzing risk factors, demographics, and 30-day perioperative outcomes. From 2005 to 2010, we identified 1251 partial nephrectomies, of which 525 were MIPN and 726 were OPN. Results: Analysis showed a decreased risk of overall morbidity, serious morbidity, and surgical site infections (SSIs); specifically superficial SSI, urinary tract infection, and bleeding (p<0.005) in MIPN than OPN. Resident and fellow versus attending only involvement was associated with increased rates of overall, serious, and nonserious morbidity, superficial and overall SSI, bleeding, and sepsis or septic shock (p<0.05). Postgraduate year (PGY) 6 residents and fellows had a significantly higher likelihood of nonserious morbidity, organ space and overall SSI, and sepsis or septic shock compared to PGY 1-5 residents. Length of stay, which was significantly shorter with MIPN than OPN (3.2 vs 5.1 days; p<0.0001), however, was associated with longer operative times (185.7 vs 209.7 minutes, p<0.001). Conclusions: This is the first report utilizing ACS NSQIP to review surgical approaches as well as the impact of trainee involvement on clinical outcomes. The increased complication rates and cost of healthcare might be mitigated by awareness, investment in surgical simulation laboratories, and competency assessment.