Oncoplastic breast-conserving surgery (O-BCS) combines oncological safety with superior aesthetic outcomes, enabling women to maintain their breast contour following partial mastectomy and other procedures. The lateral intercostal artery perforator (LICAP) flap, a muscle-sparing technique, is a procedure that utilizes excess soft tissue below the armpit to fill the cavity remaining after a lumpectomy for tumors located in the outer quadrant of the breast. We present an exemplary case of a 45-year-old female who underwent O-BCS for multifocal invasive ductal carcinoma, followed by reconstruction with the LICAP flap. The patient exhibited exceptional aesthetic outcomes following the LICAP flap procedure, preserving a natural breast contour while achieving clear surgical margins and eliminating residual cancer tissue. The efficacy and versatility of the LICAP flap technique qualify it as an effective approach that addresses the reconstructive aspects of oncoplastic breast surgery, while also achieving a successful oncological response.