Pseudotumorous types of spontaneous intracerebral haematomas are known from clinical or radiological publications. To our knowledge no study has been conducted dealing with both aspects. A series of 13 cases of spontaneous intracerebral haematomas operated upon as tumours, is reported. In 11 cases the association of atypical clinical course and atypical CT led to the diagnostic error. In 2 cases atypical CTs were erroneous despite a typical clinical course. The atypical clinical features were a progressive course or seizures. The atypical CT findings concerned prolonged hyperdensities, contrast enhancement, ring-shaped and hypodense areas. After discussion of these various findings the authors conclude that a tumour can never be excluded definitely in such cases, and advocate definitive clearing of diagnosis by operation or stereotactic biopsy.