Background:Smartphone has become an integral part of everyday life for educational and recreational purpose. A smartphone is used for playing games, internet surfing, watching movies, communicating, etc. This has lead to increased severity and prevalence of smartphone addiction among teenagers, adolescents, and young adults. Evidence points to various pathophysiological changes in upper extremity due to repetitive and continuous usage of smartphone for longer durations. Thus, this study aims to compare the effect of smartphone addiction on gross-hand dexterity in young adults. Materials and methods:160 young adults within the age group of 18-35 years were asked to fill the Smartphone Addiction Scale (SAS). Based on the scores calculated, they were classified as having mild, moderate and severe smartphone addiction. 20 subjects for each group (n=20) were randomly selected and were assessed for gross- hand dexterity using the Minnesota Manual Dexterity Test on dominant as well as the non-dominant side (N=60). The subtests used were Placing test, Turning test and One-hand turning and placing test. Results:Data was analyzed using GraphPad Instat3 software. On comparing the group means, it was observed that the severely addicted group took the longest time to complete the tests, followed by mildly addicted group and then moderately addicted group. However, the difference in means was not statistically significant. For the placing test [Group means (in seconds):severe(181.00+19.593) >mild (177.85+16.878)>moderately (175.40+16.627)], the p-value was 0.7005 on dominant side and 0.0550 on the non-dominant side[Group means:severe(200.50+22.360)> mild(191.45+14.848)> moderate (184.80+ 22.353)]. The p-value was 0.1543 for the turning test [Group means:severe (155.25+21.584) > mild (146.70+19.377)> moderate (144.20+19.339)]. For one-hand turning and placing test, the p-value was 0.0890 on dominant side[Group means on dominant side: severe (218.00+23.231) > mild