BACKGROUND: After earthquakes, individuals may increase their internet usage to cope with post-traumatic stress symptoms, potentially leading to internet addiction and sleep disturbances. AIMS: This study aims to determine the levels of post-traumatic stress disorder (PTSD), internet addiction and insomnia in earthquake survivors 1 year after the event and to explore the relationships between these variables. METHODS: This cross-sectional descriptive study was conducted between April and June 2024 through face-to-face interviews with 554 individuals who survived the February 6, 2023 earthquake in Turkey, 1 year after the event. Data were collected using the PTSD Checklist for DSM-5 (PCL-5), the Young Internet Addiction Test-Short Form (YIAT-SF) and the Insomnia Severity Index (ISI). RESULTS: A statistically significant moderate positive correlation was found between PCL-5, YIAT-SF and ISI based on the Pearson correlation test ( CONCLUSIONS: It is concluded that the severity of PTSD symptoms in earthquake survivors is associated with the severity levels of insomnia and internet addiction. Additionally, it is determined that experiencing injury or loss of a loved one during the earthquake may increase the severity of PTSD symptoms. To protect earthquake survivors from the risk of PTSD, it may be necessary to provide psychosocial support focussed on positive coping strategies for internet addiction and insomnia.