Backgrounds: Suicidal ideation is an important public health issue due to devastating mortality. In the meantime, interpersonal trust was found to be negatively associated with mental disorder and physical health. Although there is increasing evidence that interpersonal trust is a significant predictor of suicidal ideation, evidence of this association is still lacking in the developing world. The aim of this study was to test the association between interpersonal trust and suicidal ideation among older adults in China. Methods: Using a multi-stage stratified sampling strategy, 7070 older adults aged 60 and above from Shandong Province, China were recruited in this study. Socio-demographic characteristics, health status, family relationship, psychological distress, interpersonal trust and suicidal ideation in the last 12 months were obtained through face to face interviews. The association between interpersonal trust and suicidal ideation was assessed using multiple logistic regression models adjusting for socio-demographic characteristics, health status, family relationship and psychological distress. Results: 7.1% of participants reported suicidal ideation in the past 12 months, which was related to gender, resident area, marital status, educational level, self-rated economic, chronic disease, self-rated health status and family relationship within 1 month, psychological distress and interpersonal trust. After adjusting for sociodemographic factors, health status, family relationship and psychological distress, interpersonal mistrust was associated with two times odds of suicidal ideation when compared to interpersonal trust Conclusions: The interpersonal trust was associated with suicidal ideation among elderly in Shandong, China. Intervention approaches regarding inducing and promoting interpersonal trust should be developed to prevent suicide. [ABSTRACT FROM AUTHOR]