Introduction. The place of platelet antiaggregants il I the aetiology, of intracerebral hemorrhage (IH) has riot been extensively studied. Objective. To analyze the characteristics of IH inpatients treated with platelet antiaggregants and the possible clinical and prognostic differences from other primary IH. Patients and methods. A retrospective study of patients admitted to hospital with primary IH from 1985 to 1997. The cases were IH patients while being treated with platelet antiaggregants. For each case we selected Two controls with IH and similar age and IH risk factors. The following data was analyzed: start of clinical condition; type, dose, indication and duration of treatment with antiaggregants; mortality localization, volume and extension of IN to the ventricles. The last four variables were compared with the control group using the ji squared test (chi(2)) and the t-student test. Results. 21 one patients had a primary IH while being treated with antiaggregants: 20 with salicylates (17 aspirin and 3 riflusal) and one with ticlopidine. The dose of aspirin was 500 mg ol less in 90% of the cases. In the group treated with salicylates, this was given for more than 20 months in 90% of the cases. Initially, there was no clinical progression in any case. No significant differences were observed between the variable compared, although there was a tendency to greater volume, extension to the ventricles and mortality in the group treated with antiaggregants. Conclusions. More studies with larger numbers of patients are necessary to be able to confirm the tendencies observed.