Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are considered to be rare primary headache disorders. The purpose of this study was to define the clinical features, response to prophylactic treatment and efficacy of lignocaine by subcutaneous infusion for periods of acute exacerbation requiring hospitalisation. Over a period of 6 years (March 2000--February 2006) all cases of SUNCT and SUNA in neurology clinics at the Gold Coast Hospital, Australia, were reviewed. International Headache Society diagnostic criteria were used. Clinical features and response to treatment were prospectively recorded using headache diaries and magnetic resonance imaging of the brain was carried out. Twenty-four subjects with SUNCT or SUNA were identified. The incidence of these conditions was 1.2/100,000 and the prevalence 6.6/100,000. An episodic disease course was evident in 14/24 (58%) cases, whereas 10/24 (42%) had a chronic course. An aberrant vessel in close association with the fifth cranial nerve was seen in 88% of cases. A good or excellent response to lamotrigine was seen in 11/19 (58%) and was more effective in the episodic group (100%). A subcutaneous infusion of lignocaine proved completely effective on 11/14 (78%) occasions. SUNCT and SUNA are not rare conditions. Characterisation into episodic and chronic disease course appears to be of prognostic and therapeutic importance. Lamotrigine is effective in the majority of cases and subcutaneous lignocaine is useful as acute treatment for severe recalcitrant attacks.