For the past 70 years positioning and postural drainage have played an important role in increasing lung volumes, perfusion, oxygenation and mobilization of secretions. While gravity is not a primary mechanism for normal secretion clearance, it plays a major role in depth and pattern of ventilation, perfusion, and lymphatic drainage. Changing patient position, or turning patients on a regular basis, is a powerful tool in maintaining lung health in a broad range of patients. In contrast, postural drainage requires considerable investment of time, and has been shown to have limited benefit in most patients. Postural drainage has been shown to improve mobilization of secretions in patients with cystic fibrosis as well as patients who produce, and have difficulty clearing, large quantities of sputum. The benefits of postural drainage appear technique-dependent, requiring sufficient drainage time (3 - 15 min) for each position drained. The evidence does not support the use of vibration and percussion independent of active postural drainage. Exercise offers benefit in secretion clearance, which increases when combined with a program of postural drainage. In conclusion, routine turning, mobilization and exercise is important to maintain lung health in all patients, while postural drainage, properly applied, has been shown to improve secretion clearance in a relatively narrow range of patients with cystic fibrosis and excessive sputum production.