Objective <p>This study was planned to compare carpometacarpal (CMC) joint position sense, lateral pinch strength and light touch sensation in young people aged 18–25 with and without smartphone addiction.</p> Materials and Methods <p>The study included 38 individuals aged 18–25. After obtaining the socio-demographic information of the participants, thumb pain was assessed with the Numerical Pain Rating Scale (NRS), smartphone addiction was assessed with the Smartphone Addiction Scale-Short Version (SAS-SV), CMC joint position sense was assessed with the Joint Position Sense Test at 20°, 30° and 40° thumb abduction, lateral pinch strength was assessed with a pinchmeter, and light touch sensation was assessed at the distal part of the thumb, proximal phalanx and thenar regions with the Semmes–Weinstein Monofilament Test (SWMT).</p> Results <p>As a result of the study, no difference was found between smartphone addicted and non-smartphone addicted youth in terms of CMC joint positioning error and light touch sensation at 20°, 30° and 40° thumb abduction (p &gt; 0.05), but a significant difference was found in terms of lateral pinch strength and thumb pain (p &lt; 0.05).</p> Conclusion <p>This study shows that in young people aged 18–25 with smartphone addiction, lateral pinch strength decreased and thumb pain increased compared to those who were not smartphone addicted, but there was no difference in CMC joint position sense and light touch sensation.</p>