Purpose Flank hernias are uncommon hernias that are notoriously difficult to treat and technically challenging. We report a novel and successful sandwich technique to repair a large 22cm incisional flank hernia containing bowel and previous polypropylene mesh. We conducted a literature review to examine the techniques of repairing large incisional flank hernias. Methodology and Results The patient had an incisional flank hernia, measuring 22x10cm, secondary to a previous fibromyxoid sarcoma excision. He underwent an elective open hernia repair using a sandwich mesh technique (sublay fixed onto onlay) to facilitate wide mesh overlap and enhance repair strength. We discuss this technique, including pre-operative, intra-operative and post-operative photos. The patient had an uncomplicated recovery, and was discharged after five days. Abdominal binder remained for six weeks to reduce seroma risk. At two-year follow-up, there was resolution of pain with no development of infection or recurrence. Importantly, the patient’s quality of life has greatly improved. A literature review was conducted through a search of PubMed, Scopus and EMBASE databases. Eight studies were included. Recurrence rates ranged from 0% to 14.3%. Open, laparoscopic and robotic approaches were employed in 62.5%, 25% and 12.5% cases, respectively. Conclusion A sandwich mesh technique, combining sublay and onlay mesh, is effective in repairing a large flank hernia with minimal post-operative morbidity. There is a paucity of literature on the repair of large incisional flank hernias. Long-term studies are required to assess recurrence. This study contributes to the literature base around large incisional flank hernias.