When the deep inferior epigastric perforator (DIEP) flap is unavailable, autologous reconstruction of a moderate-to-large breast presents a surgical challenge. We retrospectively review our experience of unilateral breast reconstruction using double transverse upper gracilis (TUG) flaps and highlight specific technical considerations. Thirty-four patients underwent double TUG flaps for unilateral breast reconstruction between 2012 and 2020. The average patient age was 50 years and the average body mass index (BMI) was 23.1 kg/m2. In all cases, the indication for surgery was breast cancer: 31 patients had immediate reconstruction, 11 had simultaneous axillary surgery and eight had primary contralateral symmetrising surgery. Of the 68 TUG flaps, 67 (98.5%) were successful. The mean operative time was 5 h 50 min (195–460 min) and the mean combined flap weight was 551 g (279–916 g). Eight patients returned to the operating theatre in the early post-operative period and five patients underwent secondary lipofilling to address contour deformities. Most commonly (n = 22), the flaps were oriented horizontally/obliquely, with one flap anastomosed medially to the internal mammary axis and the other anastomosed lateral to the subscapular system. The internal mammary artery perforators and serratus anterior artery provided the best vessel calibre match with the TUG vessels. Double TUG reconstruction is a safe and reliable option for unilateral breast reconstruction and is an important option when the DIEP flap is unavailable.