The clinical features of SUNCT syndrome have been reviewed in 21 patients. There were 17 men and 4 women, rendering a clear male preponderance (ratio of 4.25). The mean age at onset was around 51 years. Attacks were experienced mostly in the orbital/periorbital area and always recurred on the same side, with an erratic temporal pattern and remissions of varying lengths. Most attacks were moderate to severe in intensity and burning, electrical, or stabbing in character. The attacks were regularly accompanied by prominent, ipsilateral, conjunctival injection; tearing; and rhinorrhea or nasal obstruction. There were many precipitating mechanisms. Exclusively spontaneous attacks were described in 3 patients. The usual duration of paroxysms ranged from 10 to 60 seconds, Whereas the longest duration varied from 60 to 300 seconds. The frequency of attacks during the symptomatic periods varied from less than 1 attack daily to more than 30 per hour. In the majority of patients, supplementary examinations failed to show any notable abnormality. However, 2 patients were documented to have a symptomatic form of SUNCT, with a vascular malformation in the ipsilateral cerebellopontine angle. A variety of drugs and local anesthetic blockades, inclusive of tic douloureux drugs, were tried, but a persistent, convincingly beneficial effect was generally lacking. SUNCT syndrome is in the differential diagnosis when encountering unilateral, orbital/periorbital headache syndromes.