The rapid increase in the number of smartphone users has raised concern about the negative psychosocial and physical effects of this use. A descriptive cross-sectional design was conducted to investigate the relationship between smartphone use, anxiety and insomnia among university students. A convenience sample of 404 students from one public university completed questionnaires with items from the Smartphone Addiction Scale, the Depression Anxiety Stress Scale and the Insomnia Severity Index, with some demographic data. High smartphone addition scale score was significantly associated with higher anxiety and stress scores of the Depression Anxiety Stress scale, and higher insomnia severity index score. The findings support the importance of an intervention program to promote appropriate use of smartphones and to improve sleep and psychological symptoms such as stress and anxiety among university students.