Introduction: According to the World Health Organization estimates annually in the world die due to CVI every sixth women and 10th man. This paper is the research of the correlation between changes in relative air humidity and stroke (CVA) in the Sarajevo Canton. Included are patients who experienced an acute stroke in the Canton of Sarajevo and treated in the pre hospital phase by the staff of the Institute for Emergency Medicine. Days with stroke and those without cases of stroke were compared within three years and meteorological data for those days were obtained by the Weather Bureau of Federation of Bosnia and Herzegovina. Meteorological data include measurements of average humidity every day at 7, 14 and 21 o’clock in three years. Aim: To evaluate the significance of the influence of humidity on the incidence of CVI’s. Show the trend towards CVI in the reporting period and is it correlated with the trend of change in relative humidity in those days. Correlate the incidence of stroke as determined in relation to gender, age and selected climatic parameter. Material and Methods: This article presents a retrospective study. Subjects were patients of Emergency Medical Care Institute in Sarajevo, which in the period from 2004 to 2006 had a CVI. Included are patients who had a working diagnosis of stroke for the first time or as a repeated stroke. Analysis of cases of stroke was carried out by gender, age, days and seasons by descriptive-analytical epidemiological methods. Results: In total were registered 1930 patients during three years period. According to years of research in 2004–635, 2005-616 and 2006 – 679. It was found that when testing the null hypothesis about the effects of humidity in two months with a maximum stroke in the year and days without CVI and relative humidity only in 2005 had a statistically significant effect on the incidence of stroke, while during the other two years of the study there was no impacts. It turned out that the extreme values of relative humidity of the day whether there was a rapid increase or decrees in humidity increases the incidence of stroke in all three years of research. Conclusion: Patients gender had no effect on the incidence of CVI. Seasons had no effect on the incidence of CVI. Most CVI in all three years of research was in relation to the old age and occurred in the older age group 70-79 (41.35%), where it was shown that the age of the patient influences the incidence of CVI. Extremely low relative humidity and extremely high, influence on the increase in the number of CVI. Determined is a slight correlation between the average relative humidity and CVI in single day.