Transient ischemic attack (TIA), defined as an ‘acute cerebrovascular incident requiring emergency’, is usually assessed based on the association of the age, blood pressure, clinical features, duration of symptoms, and diabetes (ABCD2) score (1,2). Some studies have demonstrated that patients with vertebrobasilar TIA have higher short-term and an identical long-term risk for stroke compared with those with hemispheric TIA (3). Also, patients with left hemispheric stroke are more often treated in the hospital than patients with right hemispheric stroke (4,5). We reported our Bulgarian experience and suggested that risk stratification and stroke frequency in first registered TIA patients with moderate risk (ABCD2 5) are associated with initially affected cerebral vascular territory and presence of modifiable risk factors. One hundred thirty consecutive TIA patients, with clinical symptoms lasting up to 60 mins were followed-up for 18 months between November 2008 and April 2010. Among them, mean age was 70·68 8·82 years and 61 (46·9%) were males. Hypertension was present in 99 (76·2%) patients, diabetes mellitus in 33 (25·4%), 36 (27·7%) had heart rhythm and conduction disorders, 53 (40·8%) were dyslipidemic, and 78 (60·0%) were smokers. Diagnosis was confirmed by neurological examinations and normal computed tomography/magnetic resonance imaging results. The ABCD2 scores were between 4 (46·2%) and 5 (53·8%). The right middle cerebral artery (MCA) was involved in 43 of the patients, the vertebrobasilar system in 46, and the left MCA in 41. Within the first three-months, strokes occurred in eight patients, and the stroke frequency was higher in patients with TIA in the right MCA and in the vertebrobasilar system. Over the 12-month period, strokes developed in 23 patients with presence of dyslipidemia in almost all cases (odds ratio: 24·61, 95% confidence interval: 5·45, 111·21). Data analysis indicated statistically significant differences between the identified cerebral vascular territories: right MCA (47·8%), vertebrobasilar system (30·4%), and left MCA (21·7%) with the higher incidence of stroke in the right MCA territory, involved initially (Fig. 1). Dimitar Maslarov* and Desislava Drenska