This paper described haemorrhagic events characterised by contrast extravasation in the procedure of mechanical thrombectomy due to various causes. Although this complication is rare, patients showed a high mortality and disability rate. There are limited reports available. We found self-limiting haemorrhage had a rather benign prognosis and balloon tamponade could effectively stop the extravasation and might reduce the death rate within 90d. The methods we adopted could be applied in the clinical practice and help neuro-interventionist cope with this complication more promptly and effectively.