Objective Technology has revolutionized the way people communicate and changed communication in many ways. The evolution of the smartphone may shed some light on this. Though smartphones are user friendly, they can be detrimental to a user’s health if they are used in an addictive manner. With easy accessibility to smartphones, dental students may fall prey to smartphone addiction (SA) which in turn may affect their social interaction. Therefore, this paper aimed to examine whether SA affects social interaction. Materials and methods A cross-sectional survey was conducted among undergraduate dental students from five dental institutions in Hyderabad. Participants received a questionnaire assessing SA [15 item-Smartphone Addiction Proneness Scale (SAPS-15)], social interaction [20 item-Social Interaction Anxiety Scale (SIAS) ). The chi-square (χ2)-test was used to determine the association between SA and social interaction anxiety. p ≤ 0.05 was considered statistically significant. Results The study comprised 470 (30.7%) males and 1060 (69.3%) females. Multiple logistic regression revealed females [1.65; confidence interval (CI) = 0.88–1.88] and third year students (2.12; CI: 1.45–2.23) had significantly higher odds for social interaction anxiety (p ≤ 0.05*). Conclusion Therefore, the present study supported the hypothesis that SA affects social interaction anxiety among undergraduate dental students.