Over the last decade Surgical Stabilisation of Rib Fractures (SSFR) gained popularity in our hospital. With increased numbers, we noted that frequently injuries were missed during primary/secondary survey and radiological imaging that were found during the surgical procedure. With this observation, the research question was formulated: What is the value of diagnostics thoracotomy or thoracoscopy during surgical stabilisation of rib fractures? In a single-centre, retrospective study between February 2010 and December 2019, trauma patients who underwent Surgical Stabilisation of Rib Fractures (SSFR) and an inspection thoracotomy were included. All radiological injuries were compared with intraoperative findings. Missed injuries that were discovered during the surgical procedure that were not analysed during primary/secondary survey or on radiological imaging were recorded and retrospectively analysed by an independent radiologist. Fifty-one patients were included. Eight patients had additional injuries; all had a diaphragmatic rupture, one patient had an additional stomach laceration, and another patient had a significant lung laceration in need of surgical repair. On a CT scan there are 7 signs of predictive value for a diaphragmatic rupture. Only 13 out of the total of 56 diaphragm rupture CT signs were confirmed on the primary CT scans of the eight patients with diaphragmatic injuries; therefore, still 77% of signs could not be confirmed by initial radiological findings. With the recent shift towards surgical stabilisation of rib fractures, an inspection thoracoscopy or thoracotomy during SSFR should be considered to minimise the incidence of missed intrathoracic injuries requiring early or late surgical treatment.