Internal jugular venous cannulation is a common procedure performed in the hospitals for monitoring and therapeutic purposes. We report an extremely rare complication of mediastinal haematoma following Internal jugular venous cannulation in a 55 years old female patient with subarachnoid haemorrhage following rupture of right p-com aneurysm. Post procedural chest X ray showed a large mediastinal haematoma occupying the right hemithorax and the patient became symptomatic in the form of development of stridor for which she had to be reintubated. Patient was managed conservatively and subsequent serial chest X- ray showed gradual resolution of the haematoma. The occurrence of mediastinal hematoma resulting from vascular injury in close proximity to the mediastinum is an extremely rare complication. It is documented in the literature in very few case reports [10]. We report this rare case to highlight the importance of supervised catheter insertion, use of ultrasound for insertion , the important role of post procedural chest X ray to detect and for early management of complications. 

Key words: Cannulation; Haematoma; Internal Jugular Vein; Mediastinum; Stridor.