Pertussis is a acute respiratory tract infection characterized by the persistent and spasmodic cough attacks. The clinical manifestations depend on the specific pathogen, the host’s immunization, and the patient’s age. Infants, especially those younger than one year, may show atypical forms of pertussis. In this report, three cases were discussed who were brought with the complaint of fever and diagnosed as pertussis with atypical course in follow-up.