Introduction. Next to locoregional control, good cosmetic outcome is one of the main goals of breast conserving treatment (BCT) for breast cancer surgery. Factors affecting cosmetic outcome are well known. The sentinel node (SN) procedure avoids lymphedema in the breast, which might influence cosmetic outcome. The aim of this study was to evaluate the cosmetic outcome of BCT after the SN procedure compared to that after axillary lymph node dissection (ALND). Methods. The subjects were 20 patients who underwent ALND and 20 patients who underwent the SN procedure. After a minimum follow-up period of 43 months, we photographed each patient. Fifteen healthy women served as control subjects. We used the percentage breast retraction assessment index (pBRA=BRA/reference length × 100) to compare cosmetic outcome. Results. The median pBRAs of the ALND group and SN group (14.3 and 6.71, respectively) significantly differed (p = 0.001). The pBRA of the SN group was comparable to the pBRA (6.1) of the control group (p=0.317). Conclusion. Cosmetic outcome of BCT after the SN procedure was superior compared to the cosmetic outcome after ALND. This is an important additional reason to implement the SN procedure in routine daily practice.