Twelve patients who had surgical removal of a cerebral haematoma had a biopsy or autopsy diagnosis of cerebral amyloid angiopathy-related haemorrhage (CAAH). Ten had a cortical biopsy at the time of surgery and eight reports of these were interpreted as showing CAA to be the cause of the haemorrhage. The diagnosis in the remaining two was made at autopsy. Six patients had a biopsy and autopsy, resulting in a 67% (four of six) biopsy sensitivity. Amyloid beta-protein (A beta) immunohistochemistry was more sensitive than tinctorial stains in detecting CAA. As previously reported in CAAH there was an excess of patients with the APOE epsilon 2 allele (33% versus 16% in a control group). Four patients (33%) were alive at 3 months. Despite surgical intervention, CAAH has a poor outcome in patients with impaired consciousness. Clinical awareness of CAAH and use of A beta immunostaining may increase the diagnostic yield from cerebral biopsy.