Rhinosinusitis is a common disorder with various etiological factors. In our clinical practice allergy seems to be a predominant cause followed by other less common causes like infection, drugs and aspirin hypersensitivity. We present a case of chronic rhinosinusitis secondary to hypothyroidism. Although hormonal causes like hypothyroidism have been proven to cause nasal congestion and rhinosinusitis, this is the first reported case of chronic rhinosinusitis in Hashimoto's thyroiditis in our center. This is a diagnosis of exclusion for chronic rhinosinusitis not responding to optimal medical therapy.