Older prisoners are the fastest growing incarcerated population with high suicide rates, yet limited information is available to inform best practices for their early risk detection and suicide prevention. Aims: The present study sought to determine the current prevalence of and factors associated with active suicidal ideation (ASI) and passive suicidal ideation (PSI) in older prisoners, and to determine if ASI and PSI were similarly associated with depression and lifetime suicide attempt Ð markers of subsequent suicide. Method: ASI, PSI, current major depressive episode (MDE), lifetime suicide attempt, and participant characteristics were assessed during interviews with 124 prisoners aged 50 years and older. Participants were assigned to one of three mutually exclusive groups: no SI, PSI only, and ASI. Results: Past alcohol dependence and fair/poor self-rated health were associated with SI. Compared with those with no SI, older prisoners with PSI (10%) and ASI (11%) were more likely to have a lifetime suicide attempt and/or MDE. However, the likelihood of experiencing either MDE or a suicide attempt did not differ between those with ASI or PSI. Conclusions: Among older prisoners, PSI and ASI may be similarly associated with markers of subsequent suicide. PSI should not be considered inconsequential and may distinguish older prisoners with elevated suicide risk.