Study Design. Observational cross-sectional study.Objective. The aim of this study was to investigate the association between text neck and neck pain (NP) in adults. Summary of Background Data. It has been hypothesized that the inappropriate neck posture adopted when texting and reading on a smartphone, called text neck, is related to the increased prevalence of NP. Methods. The sample was composed of 582 volunteers aged between 18 and 65 years. Sociodemographics, anthropometrics, lifestyle, psychosocial, NP, and smartphone use-related questions were assessed by a self-reported questionnaire. Text neck was assessed by measuring the cervical flexion angle of the participants standing and sitting while typing a text on their smartphones, using the Cervical Range of Motion (CROM) device.Results. Multiple logistic regression analysis and linear regression analysis showed the cervical flexion angle of the standing participant using a smartphone did not associate with the prevalence of NP (odds ratio [OR] ¼ 1.00; 95% confidence interval [CI]: 0.98-1.02; P ¼ 0.66), NP frequency (OR ¼ 1.01; 95% CI: 1.00-1.03; P ¼ 0.056), or maximum NP intensity (beta coefficient ¼ À5.195 Â 10 À5 ; 95% CI: À0.02 to 0.02; P ¼ 0.99). Also, the cervical flexion angle of the sitting participant using the smartphone did not associate with NP (OR ¼ 0.99; 95% CI: 0.98-1.01; P ¼ 0.93), NP frequency (OR ¼ 1.01; 95% CI: 0.99-1 . 0 2 ; P ¼ 0 . 1 3 ) , o r m a x i m u m N P i n t e n s i t y ( b e t a coefficient ¼ 0.002; 95% CI: À0.002 to 0.02; P ¼ 0.71). Conclusion. Text neck was not associated with prevalence of NP, NP frequency, or maximum NP intensity in adults.