Montelukast, selective leukotriene (LT) receptor antagonist specific for cysteinyl LT type 1 receptors, serves as an alternative treatment option for asthma and different allergic clinical conditions. However montelukast, itself, may rarely induce hypersensitivity reactions. Although rare, clinicians, especially those working in pulmonology and allergy clinics, should be aware of the potential for montelukast to cause hypersensitivity reactions. Herein, we present a 61-year-old female patient who was followed up with Samter’s syndrome and developed urticarial rashes after montelukast treatment, and montelukast allergy was confirmed by oral drug provocation test.