Background: Billions of people are using smartphone in their day today lives, essentially in poor posture. Loss of natural curvature of the cervical spine can lead to increased stresses on the spine. These stresses may in turn lead to early wear and tear, leading to degenerative changes. Imbalance in muscle activity due to altered mechanics can be a cause of pain in the musculoskeletal system of neck and shoulder in smartphone users. Therefore it is important to identify and assess the biomechanical changes that may be caused due to prolonged use of smartphones. Materials and methods: 60 (N= 60) young adults (25 males and 35 females) were divided into 3 groups of smartphone addiction (low n=20, medium n=20 and high n=20) based on their scoring of Smartphone Addiction Scale. Cervical lordosis angle was assessed using a Flexicurve, pectoralis minor muscle length using a right angled protractor and Pain using Numerical Rating Scale. Result: Data analysis showed no significance between pectoralis minor muscle length (right =0.7673, left = 0.7238) and cervical lordosis angle (p value in low group= 0.8166, p value in medium group= 0.886, p value in high group= 0.1872). However cervical pain was significantly high as the level of addiction increased (p value< 0.0001) Conclusion: There was a significant difference in the cervical pain as the level of smartphone addiction increased. Although there was no significant change in cervical lordosis angle and pectoralis minor muscle length as the level of smartphone addiction increased.