Haemorrhagic complications occurring after burr-hole procedures are diagnosed only in symptomatic patients or when postoperative imaging is performed routinely. We report the development of an intracerebral haematoma which occurred during ultrasound-guided burr-hole biopsy. Real-time ultrasound through the same burr-hole enabled us to determine the dynamics of the bleeding and its terminal volume. The operation was finished without further complications and the patient did not experience an impairment of her neurological state. Intra-operative ultrasound is capable of detecting "invisible" complications during burr-hole procedures.