The objective of this study was to investigate the long-term efficacy and safety of botulinum toxin type-A (BoNT-A) for refractory chronic tension-type headache (CTTH). An open-label, prospective study was carried out in the Department of Neurology of Kirikkale University on 28 patients (8 males, 20 females), mean age 35.6 years, diagnosed with moderate/severe CTTH refractory to preventive medications. Each patient received BoNT-A injections once in pericranial muscles. Efficacy and safety data were analysed for 28 refractory CTTH patients who were receiving concomitant headache prophylactic medications at baseline and during the study. The main outcome parameters were reduction of headache frequency and intensity over 1 year. Both parameters were significantly decreased (p<0.05) by the end of the study. Sixty-four percent of patients reported complete headache relief at the final visit, compared to 7% CTTH persisted. BoNT-A also resulted in significant reductions in analgesic consumption (p<0.05). Adverse effects were transient and local. BoNT-A was found to be an effective and safe treatment for refractory CTTH patients with concomitant headache prophylactic medications, resulting in significant reductions in headache frequency, intensity and analgesic consumption which persisted up to 1 year.