BACKGROUND: Loneliness was associated with interpersonal sensitivity, but the factors contributing to this relationship in nursing students remain unclear. This study investigated the relationship between loneliness and interpersonal sensitivity among nursing undergraduates, with a specific focus on the mediating roles played by problematic internet use and bedtime procrastination. METHOD: This study was conducted as a cross-sectional survey at a university in China between November and December 2022. Data were collected using a self-administered online questionnaire that included demographic characteristics, the Three-Item Loneliness Scale (T-ILS), the Chinese Version of Short Form of Interpersonal Sensitivity Measure (IPSM-CS), the 6-item short form of the Problematic Internet Use Questionnaire (PIUQ-SF-6), and the Bedtime Procrastination Scale (BPS). Pearson correlation analysis was employed to explore the relationships among loneliness, interpersonal sensitivity, problematic internet use, and bedtime procrastination. Structural equation modeling (SEM) was conducted using AMOS software to examine the mediating role of problematic internet use and bedtime procrastination between loneliness and interpersonal sensitivity. RESULTS: Loneliness was positively related to interpersonal sensitivity among nursing undergraduates (β = 0.44, P < 0.001). There was a significant chain mediation role of problematic internet use and bedtime procrastination in the relationship between loneliness and interpersonal sensitivity. CONCLUSIONS: The study contributed to deepening the understanding of the relationship between loneliness and interpersonal sensitivity and provided valuable insights into the improvement of interpersonal sensitivity in nursing undergraduates.