Exertional dyspnoea and shortness of breath at rest are common complaints in asthmatic patients. However, symptoms sometimes do not resolve under optimal medical treatment. In such cases infrequent causes of dyspnoea may be the underlying basis. We present a 38-year-old patient who suffered from shortness of breath not amenable to medical treatment for asthma for five years. In her medical history, the patient was on salbutamol inhalation as well as budesonide/formoterol inhalation for 5 years and the symptoms did not ameliorate. We diagnosed a right sided aortic arch after investigations. In this rare anomaly, both trachea and oesophagus might be encircled and compressed by large vessels as well as the aortic arch. Although some signs of right sided aortic arch can be recognized in chest radiograph and spirometry, accurate diagnosis is made by contrast enhanced computed tomography or angiography. Delay in diagnosis of right sided aortic arch may result in unnecessary investigations and prolonged periods of ineffective treatment. Diagnosis of right sided aortic arch leads to improvement in symptoms and withdrawal of unnecessary treatment.