Pelvic exenteration surgery remains the only curative option for recurrent rectal cancer. Microscopically involved surgical margins (R1) are associated with a higher risk of local recurrence and decreased survival. Our study aimed to develop a post hoc multidisciplinary case conference review and investigate its potential for identifying areas for improvement. Patients who underwent pelvic exenteration surgery for recurrent rectal cancer with R1 resections at a tertiary referral centre between April 2014 and January 2016 were retrospectively reviewed from a prospectively maintained database. Patients with non-rectal cancers or who underwent palliative surgery were excluded. Cases, imaging and histopathology were evaluated by a dedicated panel including colorectal surgeons, an abdominal radiologist and a gastrointestinal pathologist. R1 resections were reported in 32 of 110 pelvic exenterations. Patients with other tumours were excluded and one patient had a palliative resection. Nine male patients with 11 exenterations were included with a median age of 56 years. All patients had positive soft tissue margins, and one patient also had an involved bony margin. Failures were due to (interdisciplinary) communication problems, specific management of tumour biology (multifocality, spiculated tumours), which can lead to radiological undercalling, and inadequate surgical technical planning. In hindsight, surgery would have been withheld from one patient. A retrospective multidisciplinary case evaluation of pelvic exenteration patients with involved surgical margins led to a list of recommendations which included the need to plan for wider surgical soft tissue resections and improvement in interdisciplinary communication. Lessons learned may increase clear margin rates in future resections.