The study aims to clarify the injury profile and the causes leading to missed injuries in isolated orbital fracture patients. The hypothesis was that orbital fracture patients are prone to underdiagnosis, especially regarding injuries to other body parts. Both injury profiles and causes leading to missed injuries in isolated orbital fracture patients were evaluated in a prospective cohort study. The patients were examined systematically by the oral and maxillofacial surgeon and an on-call orthopaedic traumatologist. The patients were also referred to ophthalmology for consultation. The study includes 213 patients. Associated injuries of other body parts and additional facial injuries were found in 26.2% and 25.8% of the 213 patients, respectively. The most common injuries outside the facial region were upper limb injuries (10.8%) and traumatic brain injuries (9.4%). In all, 18.8% of the patients had at least one injury that was not suspected or diagnosed primarily. More specifically, 28.6% of injuries outside the facial region were found later, and 25.5% of additional facial injuries were not detected or suspected primarily. Of eye injuries requiring further ophthalmological care, 66.7% were found only at the ophthalmologist's examination. Isolated orbital fracture patients require comprehensive examination by traumatologists focusing on orthopaedic and intracranial injuries as well as facial injuries. Additionally, close collaboration with ophthalmologists is recommended in the early stage after injury.