Pectoralis minor adaptive shortening in healthy individuals is associated with altered scapular kinematics similar to the alterations demonstrated in individuals with subacromial impingement. This associative relationship suggests that stretching of the pectoralis minor may improve scapular kinematics and assist in the management of shoulder impingement. Several stretches for the pectoralis minor are used clinically, although it is not known which stretch optimally lengthens the muscle. The purpose of this analysis was to compare the mean length change for 3 pectoralis minor stretches. Fifty subjects without shoulder pathology were examined for the change in length of the pectoralis minor during 3 separate stretches by use of an electromagnetic motion-capture system. The stretches analyzed were a unilateral self-stretch, a supine manual stretch, and a sitting manual stretch. Each stretch was significantly different from the other two (df, 2/98; F ratio, 39.09; P < .00001), with the unilateral self-stretch demonstrating the greatest length change (2.24 cm), followed by the supine manual stretch (1.69 cm) and the sitting manual stretch (0.77 cm). Knowledge of the most effective method of elongating the pectoralis minor muscle may improve clinical decision making when targeting this anterior scapulothoracic muscle as part of intervention for or prevention of shoulder impingement.