Streptococcus pyogenes (BHS-A) is a species of Gram-positive bacteria that causes many diseases. Epidemiologically the most important are pharyngitis/tonsillitis, scarlet fever and erysipelas. Some possible complications due to streptococcal infections are purulent complications, such as mastoiditis and peritonsillar abscess, or nonpurulent complications that occur due to immune mechanisms, such as rheumatic fever, reactive arthritis, and poststreptococcal glomerulonephritis. The aim of this paper is to determine the frequency of BHS-A caused diseases in the Zadar County area in the period from 2010. to 2015. Data was processed for pharyngitis/tonsillitis, scarlet fever, erysipelas and blood culture BHS-A isolates. The data was obtained at the Public Health Institute of Zadar County. The total number of throat and nose swabs in the study period was 59 405 and the number of isolated BHS-A 6880 or 11.6%. In the study period the total number of registered people who suffered from tonsillitis/pharyngitis, scarlet fever and erysipelas was 3358. From the total number of 3366 sufferers, the most frequently occurring is pharyngitis/tonsillitis 2787 or 83%. It is evident from the results of this research that the most occurring illness in Zadar County is streptococcal pharyngitis/tonsillitis, followed by scarlet fever and then erysipelas. While the number of pharyngitis/tonsillitis cases has increased during the study period, the number of scarlet fever and erysipelas cases has declined. From the results of the research, it is clear that pharyngitis/tonsillitis and scarlet fever predominantly affect children up to the age of seven. Erysipelas is a disease that usually affects adults older than 65 years, while children are only exceptionally affected. BHS-A was very rarely isolated from blood cultures during the study period, with only 0.23% cultures containing isolated bacteria. This shows that pyogenic streptococcus in our area is extremely rarely invasive to the extent that it causes bacteremia or sepsis.