['Some micro arteriovenous malformations (AVMs) located in deep brain are undetectable. How to choose a proper timing to detect these AVMs remains unclear.', 'A 21-year-old male patient was admitted to our center for intraventricular haematoma. Digital subtraction angiographies (DSAs) were performed one week and one month respectively after his haemorrhage, but no positive results were obtained. The patient was hospitalized for re-haemorrhage six years later. A micro AVM with two diffused niduses was detected and embolised three months after his re-haemorrhage. The patient recovered without any neurological deficit.', 'Compressive effects of haematoma and spontaneous obliteration of AVMs might play pivotal roles in negative DSA results.'] Do dormant micro arteriovenous malformations lead to recurrent cerebral haemorrhage?