Background: People who use smartphones for extended periods run the risk of developing cumulative trauma. The purpose of this study was to examine the impact of using smartphones on pulmonary function and craniovertebral angle (CVA) among adolescents and compare addicted and nonaddicted ones. Methods: A cross-sectional study was carried out on 71 boys and 57 girls; Participants were categorized into two groups according to their scores on the Smartphone Addiction Scale-Short Version (SAS-SV) for adolescents. Addicted group (score > 32, n =37 M /27 F) while non-addicted group (score ≤ 32, n = 34 M/30 F). The outcome variables were craniovertebral angle (CVA), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio. Results: The findings of this study suggest a moderately strong negative relationship between smartphone addiction and CVA, as well as a weak negative association between smartphone addiction and the FEV1/FVC ratio. However, no significant correlations were found between smartphone addiction and FEV1 (r = -0.128, p = 0.149) or FVC (r = -0.019, p = 0.835). Conclusion: using smartphones for a long time had a bad impact on CVA and pulmonary function in adolescents.