An analysis of 57 patients with trigeminal neuralgia (TN) treated with microvascular decompression (MVD) is presented. Mean follow-up time was 3.1 years. Vascular compression of the trigeminal nerve root was noted in 54 cases. In the remaining 3 patients, adhesions were observed in two, whereas no obvious cause was found in one case. Among the patients with vascular compression, 43 (80%) became painfree immediately after surgery, and have remained so during the observation period. There was an indisputable relationship between the degree of observed vascular compression of the nerve and long-term complete pain relief. There was no mortality in association with the surgery. Major morbidity was seen in 3.6%, and partial facial sensory loss was seen in seven patients (12%). The implications of these findings are discussed.