Seventy-five patients were treated between March 1976 and June 1980 for classical idiopathic tic douloureux. Fifty-five patients underwent percutaneous trigeminal rhizotomy (PTR) and twenty-four had posterior fossa microvascular decompression (M VD) of the trigeminal nerve. Four patients had both procedures. In the PTR group. 4% were immediate failures, 42% had a delayed recurrence of pain, while 54% remained totally pain free with an average follow-up of 30 months. In the MVD group, 12% were immediate failures, 17% had a delayed recurrence of pain, and 71% have remained free of pain with an average follow-up of 28 months. Neither procedure can be regarded as ideal surgical treatment for patients with pain refractory to medical treatment. Percutaneous rhizotomy has an established place because of its safety, particularly in elderly patients. A high rate of recurrent pain is to be expected. Microvascular decompression has appeal in younger patients because of its non-destructive nature but the long term efficacy of the procedure is not known.