BACKGROUND: Gamma knife radiosurgery (GKR) is a safe and effective alternative to surgery for intracranial lesions. Most studies evaluating toxicity after GKR have concentrated on the delayed radiation effects. METHODS: We retrospectively reviewed 835 consecutive GKR cases for early (within 7 days) neurological complications or death. RESULTS: We identified a total of 18 patients (2.2%) who had a neurological event or death. Five (0.6%) patients developed new focal deficits, 12 (1.4%) patients experienced a seizure and there were three (0.4%) deaths. Two deaths were related to development of seizures and neurological deterioration. One death was caused by a respiratory arrest related to the patient's primary cancer. Of the five patients with neurological deficits, none had a persistent deficit. In two cases the neurological deficits were due to an increase in edema. Whether this occurred as a result of the gamma knife treatment or was the natural progression of the tumor is unclear. CONCLUSIONS: Complications after GKR are uncommon and the risk of a permanent deficit arising from an acute neurological event is exceedingly low.