Certain clinical features are known to correlate with patient outcome in acute stroke, but the potential of cranial CT scan as an aid to predicting recovery after stroke remains unclear. In a prospective study, 178 acute stroke patients admitted to Royal Perth Hospital were assessed by 4 neurologists; 150 cranial CT scans were performed and these were reviewed by an independent radiologist. CT lesion characteristics were cross-tabulated against clinical indices of patient outcome. Lesions greater than 50 cm3 in volume were associated with a 23% mortality compared to a 5% mortality for lesions smaller than 50 cm3. The mortality rate from intracerebral haemorrhage was 25% compared to 9% for other disease. Of patients whose CT scan showed a mass effect, 35% had an altered mental state at discharge compared to only 2% of those without a mass effect. Of the patients with deep white matter lesions, 35% had an altered mental state at discharge compared to only 13% of patients with lesions in other sites, and only 50% were discharged home compared to 77% of patients with lesions in other sites. CT scan features that correlated significantly with a poor outcome following acute stroke were large lesion size, intracerebral haemorrhage, mass effect and deep white matter lesions.