This study was designed to evaluate the efficacy of gabapentin (GBP) in the treatment of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome on a relatively large sample of Persian patients. Eight patients with SUNCT syndrome underwent a 4-week, open-label, daily treatment with 600-900 mg GBP. The frequency, intensity and duration of attacks were compared before and after the trial. After 4 weeks of treatment, intensity, duration and frequency of headaches were significantly reduced. In addition, five patients were completely relieved from headaches, and in the other three patients the mean intensity, frequency and duration of headaches were decreased notably. In this study, GBP was well tolerated and no unfavorable side-effects were reported. After the end of the trial all patients continued the medication, and after 3 months none reported undesired side-effects or return of the headaches to the pre-treatment status. Our patients had a significant response to GBP, and considering the other case reports on the effectiveness of GBP in the treatment of SUNCT syndrome, we propose that, taking into account the good side-effect profile and lack of interactions of GBP, this drug could be considered as an option for the treatment of SUNCT.