Acute bronchitis can last anywhere from seven to 10 days. However, it is not unusual to have a persistent cough to last a few weeks after your other symptoms have disappeared. Make sure you get plenty of rest, or your bronchitis can worsen and develop into pneumonia.
Chronic bronchitis is not curable, and can last from two months to two years. Consult a doctor to receive proper treatment for your chronic bronchitis.