Backgrounds <p>To investigate the effects of rTMS on state and trait anxiety among undergraduates with insomnia symptoms.</p> Methods <p>Forty-one participants were randomized to the active rTMS group (<i>n</i> = 21) or sham group (<i>n</i> = 20). 32 participants completed all assessments and were included in the final analysis (Active group: 17; Sham group: 15). Participants received 1&#xa0;Hz rTMS interventions targeting the left dorsolateral prefrontal cortex for 2 weeks, comprising 10 sessions (active vs. sham stimulation). Sleep quality and anxiety were assessed using the Pittsburgh Sleep Quality Index (PSQI) and the State Trait Anxiety Inventory (STAI) at baseline(T0), post-intervention(T1), and 8 weeks’ follow-up(T2).</p> Results <p>Mixed ANOVA results showed that, following the intervention, compared to the Sham group, the Active Group showed significant improvements in PSQI and STAI-S scores, and the Group×Time interaction effect was significant (PSQI: <i>F</i> (2, 60) = 5.27, <i>P</i> = 0.008; STAI-S: <i>F</i> (2, 60) = 9.09, <i>P</i> &lt; 0.001). Simple effects showed that at both T1 and T2, the PSQI of the Active group was lower than that of the Sham group (<i>P</i> &lt; 0.01); at T2, the STAI-S of the Active group was lower than that of the Sham group (<i>P</i> &lt; 0.05).</p> Conclusions <p>Compared with sham stimulation, 1&#xa0;Hz rTMS can effectively improve insomnia and state anxiety among undergraduates, and the improvement effect persists at the 8-week follow-up.</p> Trial registration <p>The effect of transcranial magnetic stimulation on cognitive flexibility in college students with insomnia (ChiCTR2400081263, 2024/02/28) URL: <a href="https://www.chictr.org.cn/showproj.html?proj=202951">https://www.chictr.org.cn/showproj.html?proj=202951</a> (Retrospectively registered).</p>