Aims and Objectives: This study aimed to analyse the prevalence and factors associated with suicidal ideation among family caregivers of people with mental disorders.; Background: Studies conducted with family caregivers of people with dementia and cancer point out a high prevalence of suicidal ideation among these subjects; however, this aspect has not yet been investigated among family caregivers of people with mental disorders.; Design: This is a cross-sectional study, conducted with 537 family caregivers of patients from 16 Psychosocial Care Centers (CAPS) of the 21st Health Region of the state of Rio Grande do Sul, Brazil.; Methods: Question 17 of the Self-Reporting Questionnaire (SRQ-20) was used for suicidal ideation screening. The prevalence of suicidal ideation was calculated according to sociodemographic and care variables, with confidence interval estimate (95% CI). Crude and adjusted odds ratios were calculated by logistic regression. The Guidelines to Reporting of Observational Studies in Epidemiology (STROBE Statement) was adhered in this study (See File S1).; Results: The prevalence of suicidal ideation found in this study for the 30 days preceding the interview was 12.5% (95% CI: 10-15). The factors associated with the outcome were lower age, lower schooling, feeling of burden, self-report of stress problem and dissatisfaction with family relationships.; Conclusion: The prevalence of suicidal ideation among the studied family caregivers was high and strongly associated with issues regarding care, showing the need for interventions that provide support.; Relevance For Clinical Practice: Nurses are a large part of the workforce of the community mental health services. The careful characterisation of the subjects who show suicidal ideation, as performed in this study, may reveal specificities capable of refining the diagnostic potential for establishment of action plans in a timely manner, avoiding possible attempts or even the consummation of suicide.