Unilateral breast reconstruction after mastectomy provides the challenge of achieving symmetry with the opposite side. Reduction mastopexy is a common balancing procedure for the contralateral breast used to achieve pleasing and symmetrical breasts. Although symmetry is the ultimate goal, some women have a hypoplastic and/or ptotic contralateral breast, and the recreation of this shape would therefore not be desirable. From April of 2000 to April of 2005, a total of 158 patients underwent postmastectomy breast reconstruction using either free deep inferior epigastric perforator flaps (n = 142) or superficial inferior epigastric artery flaps (n = 16) at Chang Gung Memorial Hospital. Of the 158 patients, 19 (12.0 percent) underwent endoscope-assisted placement of implants into the contralateral breast at the same surgical stage to form a more pleasing breast mound. Mean patient age was 46.1 +/- 7.6 years. All patients had a slender body habitus, with small to medium-sized breasts. Saline-filled implants were placed in a submuscular position with the assistance of endoscopy. Five different incisions for access were used: transaxillary (n = 6), Port-A-Cath catheter scar (n = 4), inframammary (n = 1), biopsy scar (n = 1), and transmidline (n = 7). The success rate was 100 percent, with complete survival of the 19 flaps. In three patients, revision procedures were carried out at 12 to 44 months' follow-up because of implant leakage, capsular contracture, and nipple ptosis (one patient each). The remaining patients were highly satisfied with the cosmetic result, and symmetry was achieved, with soft, natural appearing breasts during the follow-up period of 29.2 +/- 16.9 months. The transmidline approach was superior to the other routes, because no additional scar was produced and access was easier. Contralateral breast augmentation at the same stage with deep inferior epigastric perforator or superficial inferior epigastric artery flap surgery can be performed with high success rates and poses no surgical risks or morbidity to patients. The combined procedure does not significantly extend the time of operation, and aesthetically pleasing results and symmetry can be achieved and sustained over the long term.