Introduction and importance: This is the first case of delayed tracheal perforation post total thyroidectomy in the context of previous radiotherapy to the neck. Such a presentation can be easily misdiagnosed and managed as a seroma at significant risk to the patient, as the latter had no precipitating factors and cardiorespiratory compromise. There are nineteen previously described cases of delayed tracheal injury post thyroidectomy of variable severity and variable intervention. Case presentation: A 51-year-old man presented with non-tender anterior neck surgical emphysema initially diagnosed on bedside ultrasound and plain X-ray, 22 days following total thyroidectomy and central neck dissection. His background was significant for childhood acute lymphoblastic leukaemia requiring chemotherapy and cranio-spinal radiotherapy. He underwent total thyroidectomy, for multiple bilateral thyroid nodules found on cranio-spinal MRI surveillance concerning for follicular neoplasm. There were significant amount of adhesions tethering the thyroid secondary to prior radiotherapy but no tracheal injury intra-operatively. Clinical discussion: At presentation, no source of air leak was identified on Computer Tomography. He failed conservative management. During surgical exploration, a 2 mm tracheal perforation at the right cricothyroid joint was closed with the right sternothyroid muscle due to the proximity of the perforation with the recurrent right laryngeal nerve. Tisseel was applied over the repair. He recovered without further complications. Conclusion: Sudden onset neck swelling post thyroidectomy in the context of significant scaring from radiotherapy, should raise the suspicion of surgical emphysema in the neck patients and confirmed with plain x-ray. Such patients should have multidisciplinary tertiary care.