<p>Previous research has consistently demonstrated that emotional abuse is a robust predictor of adolescent suicidal ideation. However, few studies have explored the bidirectional relation between changes in emotional abuse and suicidal ideation at the within-person level, as well as the underlying mediating mechanisms. This longitudinal study examined the reciprocal relations between emotional abuse and suicidal ideation, along with the potential mediating role of self-disgust, by disentangling between- and within-person effects. A total of 4731 students (44.9% girls; Mage = 10.91 years, SD = 0.72) participated in a four-wave longitudinal study with 6-month intervals. Results from random intercept cross-lagged panel modeling indicated significant positive associations between emotional abuse, self-disgust, and suicidal ideation at the between-person level. At the within-person level, findings revealed that emotional abuse directly predicted suicidal ideation, and suicidal ideation also directly predicted emotional abuse. Emotional abuse also indirectly predicted suicidal ideation via self-disgust, while suicidal ideation indirectly predicted emotional abuse through self-disgust. These findings emphasize self-disgust as a central psychological mechanism in the bidirectional relations between emotional abuse and suicidal ideation. Targeted interventions reducing self-disgust and fostering a healthier self-concept could be crucial in breaking this harmful cycle, ultimately protecting adolescents from escalating emotional abuse and suicidal thoughts.</p>