The aim of the present study is to evaluate the main causes underlying recurrent respiratory tract infections during childhood retrospectively. The records of 204 patients out of 6935 subjects who were admitted to our clinic between the years 1994-1999, with complaints of recurrent respiratory tract infections were examined. The patients were divided into three groups depending on their complaints during admission: Children with symptoms of only upper respiratory tract infection (group I), children with symptoms of only lower respiratory tract infection (group II) and children with symptoms of upper and lower respiratory tract infection (group III). The subjects consisted of 204 children, 132 male and 72 female with a median age of 3 years. Asthma and allergic diseases were the most common causes (45%) of recurrent complaints of respiratory tract while primary immunodeficiencies were determined as the second frequent cause (37.2%). Anatomic-obstructive diseases (9.3%) and the nutritional deficiency of micronutrient (8.3%) were determined as the other primary factors causing recurrent complaints of respiratory tract. Asthma and allergic diseases, primary immunodeficiencies and anatomic-obstructive factors, as well as nutritional zinc and iron deficiencies seems to be the major causes underlying recurrent respiratory tract infection in childhood.