Postoperative neurosonography was performed in 69 babies and children after osteoclastic neurosurgery for primary cerebral tumors. Astrocytoma of the posterior fossa (26 cases) and medulloblastoma (25 cases) were frequent histological findings. Early postoperative bed-side examinations revealed reliably complications such as cerebral hemorrhage, edema or hygroma. Postoperative baseline studies were performed and reliability of sonographic criteria for tumor recurrence, such as high echogenicity and dense echotexture, were established. Regressive tissue changes under the usual postoperative cerebral radiation therapy and chemotherapy included transient increase in perifocal edema followed by tumor shrinking and cystic lesions or calcifications. Shunt dynamics were controlled by morphometrical studies of ventricular size. Long-time follow-up examinations were performed in most cases and covered periods of up to 4 years. Sensitivity of neurosonography for tumor recurrence was superior to non-contrast computed tomography; there were no false positive findings as proven by CT and magnetic resonance.