Increase in intracranial pressure due to brain oedema is one of the most frequent complications of subarachnoid hemorrhage (SAH), apart from vasospasm and hydrocephalus. Up to now the administration of corticosteroids at various dosages has been the standard therapy for brain oedema. With this retrospective study we tried to answer the question whether the administration of dexamethasone at high dosage in patients with SAH bears an increased risk of medical complications such as infections, gastrointestinal bleeding and diabetes mellitus. 171 consecutive patients of our intensive care unit, 51 men and 120 women (average age 52.4 +/- 13.6 years) were included in the study. 107 patients received dexamethasone in high doses according to Gobiet's scheme. 64 patients who were not given any steroids formed the control group. Almost the same frequency of gastrointestinal bleeding was registered in the steroid group (2.8%) and in the control group (3.1%). No increase in diabetic problems was found in the steroid group, either. The steroid group showed an increase in infections (38.3% compared with 28.1% in the control group; p less than 0.001). The increase, however, was entirely due to the more frequent occurrence of urinary tract infections (14.0% vs. 4.7%). Dexamethasone therapy at high dosage bears no increased risk of medical problems in patients with SAH, except for a greater number of urinary tract infections. However, stomach ulcer prophylaxis and monitoring of blood sugar levels and electrolytes are deemed necessary.