BackgroundFor patients with small breasts, breast-conserving surgery (BCS) and unilateral nipple-/skin-sparing mastectomy (N/SSM) with breast reconstruction may result in visible breast deformities or asymmetry, and contralateral breast augmentation often require a two-staged operation. We propose a novel endoscopic technique, direct-to-implant breast reconstruction and simultaneous contralateral breast augmentation (DTI-BR-SCBA), and report its short-term safety and cosmetic outcomes.MethodsIn this prospective study, patients with early breast cancer who underwent endoscopic DTI-BR-SCBA between November 2020 and August 2022 were followed for more than 3 months to analysed short-term postoperative safety (complications and oncological safety) and cosmetic outcomes (doctor-assessed results by Ueda scale and patient-reported results by Breast-Q scale).ResultsA total of 33 patients, including 30 treated with endoscopic prepectoral DTI-BR-SCBA, 1 with endoscopic dual-plane DTI-BR-SCBA and 2 with endoscopic subpectoral DTI-BR-SCBA, were analysed. The mean age was 39.7 ± 6.7 years. The mean operation time was 165.1 ± 36.1 min. The overall surgical complication rate was 18.2%. All complications were minor, including haemorrhage (3.0%), cured by compression haemostasis, surgical site infection (9.1%), cured by oral antibiotics, and self-healing nipple-areolar complex ischaemia (6.1%). Furthermore, rippling and implant edge visibility occurred in 6.2% of them. The outcome was graded as “Excellent” and “Good” in 87.9% and 12.1% of patients in the doctor cosmetic assessment, respectively, and patient satisfaction with breasts was significantly improved (55.0 ± 9.5 vs. 58.8 ± 7.9,P= 0.046).ConclusionsThe novel endoscopic DTI-BR-SCBA method may be an ideal alternative for patients with small breasts because it can improve cosmetic results with a relatively low complications rate, which makes it worthy of clinical promotion.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12957-023-03089-4.