A computer-assisted technique was developed for CT-guided stereotactic microsurgical resection of small intracerebral lesions. An original stereotactic retractor was developed to work with the Riechert-Mundinger's equipment for precise localisation, safe exposure and microsurgical removal of these tumours. A software-program was developed to work on an ordinary IBM-compatible PC/AT. It assisted the procedure from treatment planning till the end, including tumour excision, and provided computerized support for the removal of pathological tissues within the CT-defined boundaries of the lesion. 6 patients, harbouring supratentorial intracerebral lesions underwent surgery using this technique. 2 of them suffered from brain metastases, in 1 patient a cavernous angioma was removed, 2 patients had glial tumours, and in the last patient only radiation necrotic tissue was found to be the cause of ring-enhanced lesion, which had been suspected to be a recurrent glioma. Their largest dimensions varied between 18 and 30 mm and the age of the patients ranged from 15 to 52 years. In 2 cases the lesions were localised deeply in the region of basal ganglia and thalamus. In the remaining patients the tumours were rather superficial, infiltrating subcortical white-matter close to the central sulci. There was no mortality nor significant morbidity following the procedure, the Karnofsky Performance Status (KPS) cumulative scores being either unchanged (in 3), or improved (in 3 patients). Current state and modern concepts in image-guided open stereotactic methodology is discussed.