OBJECTIVES: To examine the frequency of re-resections and describe risk characteristics: invasive carcinoma or carcinoma in situ (CIS), palpability of the lesion, and neoadjuvant chemotherapy. RESULTS: 1703 breast conserving surgeries were performed: 1575 primary breast conserving surgeries (BCS), and 128 diagnostic excisions (DE). 176 BCS (11.2% [9.6; 12.7]) and 100 DE had inadequate margins indicating re-resection. The overall re-resection rate was 16.2% [14.5; 18.0]. 10.3% of invasive carcinoma BCS patients, and 28.6% CIS patients underwent re-resection (relative risk (RR) 2.8 [1.9; 4.1]). Invasive lobular carcinoma (ilc) had an RR of re-resection of 2.5 [1.7; 3.8], compared with invasive ductal carcinoma (idc). CONCLUSION: Overall 11.2% of the BCS patients needed a re-resection. For isolated CIS (28.6%), RR of re-resection was almost three times as high compared to invasive carcinoma (10.3%). Ilc had an RR of re-resection of 2.5 compared to idc. Palpability and neoadjuvant chemotherapy did not significantly influence the risk of re-resection.