The aim of this study was to investigate whether there is an association between text neck and neck pain in young adults. Observational cross-sectional study with 150 18-21-year-old young adults from a public high school in the state of Rio de Janeiro was performed. In the self-report questionnaire, the participants answered questions on sociodemographic factors, anthropometric factors, time spent texting or playing on a mobile phone, visual impairments, and concern with the body posture. The neck posture was assessed by participants' self-perception and physiotherapists' judgment during a mobile phone texting message task. The Young Spine Questionnaire was used to evaluate the neck pain. Four multivariate logistic regression models were fitted to investigate the association between neck posture during mobile phone texting and neck pain, considering potential confounding factors. There is no association between neck posture, assessed by self-perception, and neck pain (OR = 1.66, p = 0.29), nor between neck posture, assessed by physiotherapists' judgment, and neck pain (OR = 1.23, p = 0.61). There was also no association between neck posture, assessed by self-perception, and frequency of neck pain (OR = 2.19, p = 0.09), nor between neck posture, assessed by physiotherapists' judgment, and frequency of neck pain (OR = 1.17, p = 0.68). This study did not show an association between text neck and neck pain in 18-21-year-old young adults. The findings challenge the belief that neck posture during mobile phone texting is associated to the growing prevalence of neck pain.