Aim: TO STUDY BRAIN NATRIURETIC PEPTIDE (BNP) LEVELS IN THREE SUBGROUPS: patients having stroke with hypertension (HT), those having stroke without HT, and those with HT alone. We also tried to identify whether BNP levels predict the length of stay in hospital and mortality., Materials and Methods: The groups were formed by patients who had been admitted to the emergency department in the first 4-12 h after the onset of symptoms. There were 30 stroke patients with a history of HT (group I), 30 stroke patients without a history of HT (group II), and 20 HT patients without stroke (group III). Patients with congestive heart failure, chronic cor pulmonale, severe valvular heart disease, chronic renal failure, liver insufficiency, diabetes mellitus, atrial fibrillation, and those with a history of stroke were excluded from the study since these diseases can affect the plasma BNP levels., Results: The demographic characteristics, except the age distribution, were similar among the groups. The mean BNP levels in the three groups were 168.8 +/- 223.9 pg/ml, 85.0 +/- 75.1 pg/ml, and 84.8 +/- 178.3 pg/ml, respectively. The differences between the groups were statistically significant., Conclusion: The mean BNP levels were affected by HT and/or stroke. The simultaneous presence of HT and stroke results in a more significant increase BNP than the presence of either stroke or HT alone. When diseases that can affect the plasma BNP levels are excluded, the BNP levels in stroke patients without a history of HT are similar to the levels seen in patients with only HT.