Nocardia brain abscess is a rare intracranial lesion and has been reported in immunocompromised patients. An optimal treatment approach has not been established. However, early diagnosis and appropriate antimicrobial therapy are very important factors for a good outcome. We report two unusual cases of Nocardia brain abscess simulating brain tumour in immunocompetent patients. One of the cases was presumed to be a primary brain tumour and the other a metastatic brain tumour. They underwent surgical gross total resection. After Nocardia asteroides was seen on Gram's stain and subsequently identified by culture, appropriate antibiotic therapy was initiated.