The authors review the results of various surgical techniques in relation to mortality and morbidity in 100 consecutive cases of brain abscess and subdural empyema. The mortality rate is the same with total excision and fractional drainage of brain abscesses, although in acute and subacute cases slight differences between both techniques are seen. In terms of morbidity, fractional drainage appears to be more favourable than total excision. The authors believe that factors other than surgical procedure influence mortality in cases of brain abscess and subdural empyema. These factors are defined in detail.