Purpose: Although there has been a significant increase in the use of oncoplastic surgery (OPS), data on the postoperative safety of this approach are limited compared to traditional lumpectomy. This study aimed to compare the immediate (30-day) postoperative complications associated with OPS and traditional lumpectomy. Methods: An analysis of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was performed on women with breast cancer who underwent OPS or traditional lumpectomy. Logistic regression was used to explore the effect of type of surgery on the outcome of interest. Results: A total of 109,487 women were analyzed of whom 8.3% underwent OPS. OPS had a longer median operative time than traditional lumpectomy. The unadjusted immediate (30-day) overall complication rate was significantly higher with OPS than traditional lumpectomy (3.8% versus 2.6%, p < 0.001). After adjusting for baseline differences, overall 30-day postoperative complications were significantly higher amongst women undergoing OPS compared with traditional lumpectomy (OR 1.41, 95%CI 1.24–1.59). Factors that were independent predictors of overall 30-day complications included higher age, higher BMI, race, smoking status, lymph node surgery, neoadjuvant chemotherapy, ASA class ≥ 3, in situ disease, and year of operation. The interaction term between type of surgery and operative time was not statistically significant, indicating that operative time did not modify the effect of type of surgery on immediate postoperative complications. Conclusions: Although there were slightly higher overall complication rates with OPS, the absolute rates remained quite low for both groups. Therefore, OPS may be performed in women with breast cancer who are suitable candidates.