Purposes: To examine whether neuroticism moderates the relationship between negative life events and suicidal ideation. Methods: A stratified one-stage cluster sampling produced a representative sample of students who attended public high schools. During the initial assessment, 618 high school students (302 boys, 316 girls) completed the following 3 scales to assess negative life events, neuroticism and suicidal ideation: ⑴ adolescent life events quetionnaire-revised (ALEQ-R), ⑵ NEO five factor inventory-neuroticism subscale (NEO-FFI-N), ⑶suicidal ideation questionnaire (SIQ). Researchers returned to the schools to meet with students every three months for the subsequent 21 months (i.e., 3months, 6 months, 9 months, 12 months, 15 months, 18 months and 21 months). At each of these follow-up assessments, students completed each of the following questionnaires: (1) SIQ, (2) ALEQ-R. Data were analyzed using hierarchical linear modeling analyses. Our dependent variable was within-subject fluctuations in SIQ scores during the follow-up interval. Our primary predictors of SIQ were fluctuations in ALEQ-R scores during the follow-up interval (STRESS), and NEO five factor inventory-neuroticism subscale (NEO-FFI-N). As NEO-FFI-N is a between-subject variable, NEO-FFI-N scores were standardized prior to analyses. As STRESS is a within-subject predictor, ALEQ-R scores were centered at each participant’s mean prior to analyses such that STRESS reflects upwards or downwards fluctuations in an adolescent’s level of stress compared to his/her mean level of stress. Results: Hierarchical linear modeling analyses indicated that after controlling the effects of initial levels of suicidal ideation and gender on suicidal ideation, a non-significant main effect of neuroticism arised (? = .59, F(1, 557)= 3.05, p > .05), while a significant main effect of negative life events (? = .08, F(1, 2963) = 37.93, p < .001) appeared. Additionally, a significant two-way, cross-level interaction emerged between negative life events and neuroticism (? = .03, F(1, 2963) = 4.35, p < .001). Conclusions: The association between negative life events and suicidal ideation is moderated by nueroticism. Adolescents who had higher levels of neuroticism reported greater elevations in suicidal ideation following elevations in negative life events than other adolescents did.