Breast-conserving surgery (BCS) is a well-established treatment for early breast cancer. However, rates of BCS differ in different countries and institutions. This study attempts to find the factors affecting BCS in a local acute care hospital. To this end, 389 patients with early breast cancers treated between 2000 and 2002 were enrolled. Indications for mastectomy were more likely to be documented by breast surgeons (45%) than by other surgeons (30.6%) (P = 0.052). Univariate analysis showed that patients who had smaller tumours, were operated on in 2002 and were operated on by breast specialists were more likely to have undergone BCS. Multivariate analysis, after exclusion of patients with compelling indications for mastectomy, showed that the year of operation (p < 0.001) and the surgeon's subspecialty (p = 0.003) remained independent predictors of BCS. Thus, the surgeon has a crucial role in increasing the BCS rate in the treatment of early breast cancer.