Background The transverse upper gracilis (TUG) flap has gained increasing acceptance as a reliable option for breast reconstruction, specifically in patients without adequate abdominal tissue. Three major flap designs of the upper gracilis flap have been proposed to balance volume needs with flap vascularity. A systematic review was performed to identify outcomes of the major gracilis flaps: TUG, vertical-transverse upper gracilis (V-TUG), and longitudinal gracilis myocutaneous (LGM) flaps. This study is the first and only systematic review to date reviewing the variations of the upper gracilis flap in microsurgical breast reconstruction. Methods A systematic review of the literature was conducted using PubMed database from 1966 through 2015. Inclusion and exclusion criteria were applied. Outcomes assessed included total flap volumes, additional breast procedures to achieve intended breast volume, and complication rates. Results A total of 485 gracilis-type flaps were performed in 335 patients. V-TUG flaps provided the largest mean flap weights and did not require additional lipofilling or implant placement, whereas the majority of TUG flaps (50.6%) required additional fat grafting or implant placements. All flap types demonstrated a low incidence of donor-site morbidity. Overall flap loss rate was low; TUG flaps reported 2.3% total and 2.0% partial flap losses, while V-TUG and LGM flaps reported no flap losses. Conclusion This review found V-TUG yielded highest mean flap weights and did not require additional breast augmentation procedures as compared with the TUG. Also, the V-TUG was a safer donor-site option with fewer flap and donor-site morbidities.