A series of 66 patients with trigeminal neuralgia (TN) treated by microvascular decompression (MVD) is analyzed in order to define the importance of various prognostic factors. A typical pattern of pain, presence of facial hypaesthesia and previous ablative trigeminal procedures showed an unfavorable influence on the results of MVD. Duration of symptoms was longer in patients who failed to benefit from MVD. Pain distribution and the type of vascular compression did not influence the outcome.