This study was conducted to examine the effects of Evjenth-Hamberg stretching of the sternocleidomastoid, upper trapezius, and pectoralis major on the lung function of adults with forward neck posture. The subjects were 20 adult students in P university located in Pohang, Korea, whose degree of head forward displacement measured according to NEW YORK state posture test was mild. The subjects were randomly and equally assigned to the Evjenth- Hamberg Stretching group (EHSG, n=10) and the control group (CG, n=10). Their forced vital capacity (FVC), slow vital capacity (SVC), and maximal voluntary ventilation (MVV) were measured before and after the experiment. In within-group comparison, only the EHSG experienced statistically significant improvement in FVC, forced expiratory volume in the first second (FEV1), and peak expiratory flow (PEE) after the experiment, compared to before the experiment (.05<p). In between-group comparison, the PEE of EHSG was statistically significantly higher than CG (.05<p). Regarding SVC, only the EHSG experienced statistically significant improvement in inspiratory vital capacity after the experiment, compared to before the experiment. With regard to MVV, only the EHSG experienced statistically significant improvement in their tidal volume during maximal voluntary ventilation after the experiment compared to before the experiment. Our results indicated that Evjenth- Hamberg stretching was an effective physical therapy intervention to improve the lung function of adults with FHP by correcting their head forward displacement.