A retro- and prospective study was carried out in 150 patients who underwent surgery for benign (grade I) intracranial meningiomas (ICM). The mean duration of the follow-up was of 4 years. The subjects were divided into 4 groups according to the intervals of follow-up examination. The following variables were analysed: preoperative (clinical and paraclinical diagnosis), operative (macroscopic investigation) and postoperative (complications, sequelae, recurrences). The data were statistically processed. Conclusions are drawn concerning early results as well as predictors of long-term prognosis. Immediate improvement of the neurological and mental status was noted in 51% of patients. Late favourable outcome was found in only 35% of patients, demonstrating a tendency of late worsening. Postoperative morbidity includes complications (21%), sequelae (32%) and recurrence (22%). Predictor criteria in operated ICM patients are: onset type of illness, preoperative score, tumor location, edema and excessive vascularization of the brain as inspected at operation, early and late sequelae. Histological predictors for recurrence are: nuclear pleiomorphism, cellular mitoses, cell agglomerations. The frequency of recurrence, regardless of the operative technique, demonstrates the tendency toward malignancy of many of these tumors.