BACKGROUND: With the increasing use of social media, social media addiction (SMA) has become a pressing issue and is associated with multiple negative outcomes. Lack of mindfulness has been shown to be associated with an increased risk of SMA, yet such an association has never been explored among nurses in China. METHODS: From December 4, 2022 to March 14, 2023, a cross-sectional study was conducted in 29 hospitals in Hunan Province, China. A total of 1,141 nurses were recruited and completed the online questionnaires. Mindfulness and SMA were assessed by the Mindful Awareness Attention Scale (MAAS) and Social Networking Service Addiction Scale (SNSAS), respectively. Multivariate linear regression analysis was used to explore the association between mindfulness and SMA, and other influencing factors of SMA. RESULTS: The nurses had an average score of 68.02 ± 11.86 for mindfulness and 46.15 ± 15.09 for SMA. The results of linear regression analysis showed that lower levels of mindfulness (β = -0.06, CONCLUSIONS/APPLICATION TO PRACTICE: Our study shows a generally moderate level of SMA among nurses in Hunan Province, which was influenced by mindfulness, working years, and workplace violence. Mindfulness-based interventions may be effective interventions to alleviate nurses' SMA. Special attention should also be paid to nurses with shorter working years and those who experienced workplace violence.