Introduction. Anterior bilateral temporomandibular joint dislocation is not an uncommon occurrence and has been reported before. However, its diagnosis can easily be overlooked, especially by clinicians who are unfamiliar with this pathology. Continuous discussion of the pathology is required to prevent delays in diagnosis, which can lead to long-term sequelae for the patient. Case presentation. We present the case of a 66-year-old Somali woman who experienced a bilateral anterior temporomandibular joint dislocation after a general anesthetic for an exploratory laparotomy for excision of a pelvic sarcoma. She first presented in the intensive care unit with preauricular pain and an inability to close her mouth, and was initially misdiagnosed and treated for a muscle spasm. The cause of her misdiagnosis was multifactorial - opioid-related sedation, language and cultural barrier, and unfamiliarity with the pathology. Her diagnosis was proven 18 hours after the completion of surgery with a plain X-ray. A manual closed reduction was performed with minimal sedation by oral surgery. Conclusion: We provided an in-depth discussion of temporomandibular joint dislocation and suggest a simple test that would prevent delayed diagnosis of temporomandibular joint dislocation in any patient undergoing general anesthesia. A normal mandibular excursion should be tested in every patient after surgery in the postoperative care unit, by asking the patient to open and close their mouth during the immediate postoperative recovery period or passively performing the range of motion test.