Objective: We present an educational technique for the safe completion of complete cytoreduction of diaphragmatic disease for the management of advanced ovarian malignancy. Methods: We demonstrated these steps with attention to anatomical landmarks and surgical approaches, considering intraoperative and postoperative morbidity and mortality. Results: We present the case of a 49-year-old female patient diagnosed with suspected stage 3C ovarian malignancy following diagnostic laparoscopy. We demonstrate the surgical application of the Pringle manoeuvre, type 3 liver mobilisation, and full-thickness diaphragmatic resection. This was completed with a primary closure technique, with integrity ensured through the performance of an air test and Valsalva manoeuvre. Final histology confirmed a serous borderline tumour with invasive implants within a port site nodule (stage 4A). Conclusion This technique affirms the essential skills in gynaecological oncology training and details a challenging case requiring advanced surgical skills and knowledge, with specific consideration for intraoperative multidisciplinary decision-making.