CASE REPORT: A 5-year-old Malay boy with a history of recurrent pneumonia, presented with productive cough, fever and worsening tachypnoea. Physical examination revealed coarse crepitations, reduced breath sounds and clubbing. Biochemical investigations showed that he had respiratory type 2 failure as a result of bronchiectasis. Sweat conductivity done twice was raised supporting a diagnosis of CF. Other investigations such as bronchoscopy to look for congenital anomaly of the lung, infectious disease screening and tuberculosis, fungal and viral culture and sensitivity were negative. Further cascade screening revealed high sweat conductivity results in his siblings.