Rotavirus infection is the major cause of fatal diarrhea among children younger than five years. We aimed to determine the frequency of rotavirus infection according to age, gender and month of the year. From April 2008 through March 2013, 3,106 fresh stool specimens of children under the age of 16 years were tested for rotavirus antigen, and rotavirus antigen was detected as positive in 422 (13.6%) patients. Half of the patients (208/422, 49.3%) were younger than two years. 40.9% (173/422) of all rotavirus gastroenteritis cases were detected in winter months. The ratio of rotavirus positivity in all laboratory studies was highest (19.3%) in February.