Primary immunodeficiency diseases (PIDs) are a heterogeneous group of diseases characterized by increased susceptibility to infections. Although patients frequently present with upper and lower respiratory tract infections, they may also present with severe and/or resistant infections in uncharacteristic presentations. A delay in diagnosis is common due to the perception of PIDs as rare congenital diseases, heterogeneity of the diseases, and lack of awareness. We present here a case of newly diagnosed primary immunodeficiency with necrotizing fasciitis. The patient was diagnosed with PID with unusually presenting infections. Therefore, increasing awareness and cooperation between different clinics is very important. PID should be kept in mind among the differential diagnoses during the investigation of long term, severe, recurrent/treatment resistant and unusually presenting infections. These cases should be consulted with an immunologist.