Adenoid cystic carcinoma (ACC) of the trachea is rare; it represents 1% of all respiratory tract cancers. It is generally considered as a slow-growing, with prolonged clinical course. Most patients present with dyspnea, and the symptoms often mimic those of asthma or chronic bronchitis. Surgical resection is the mainstay of treatment often combined to radiotherapy because of close surgical margins. When surgery is not possible, most tumors respond to radiotherapy alone which often results in long periods of remission. There is no consensus on the best treatment for locally advanced inoperable ACC of trachea. This case report describes a 51-year-old woman unresectable ACC of trachea due to comorbid conditions, successfully managed by intensity modulated radiotherapy. At 8 months follow-up, the patient is healthy and asymptomatic.