The study findings provide preliminary support for an association between high levels of self-reported loneliness and a greater risk for suicide compared with inmates who did not report feeling lonely. Self-reported loneliness was also strongly associated with other predictors of self-harm, namely hopelessness and depression. If the reliability of these findings is supported in future studies, they have implications for the management of prisoners identified at risk of suicide or self-harm; for example, the use of isolation, which potentially exacerbates feelings of loneliness, should be used with caution. Screening assessment should examine the ongoing stressors prevalent within the prison environment, including loneliness, changes in social support, and levels of depression and hopelessness. It is also important that prisons provide opportunities for inmates to maintain supportive social contacts with family members and friends while they are in custody. The study involved 62 randomly selected male prisoners held on remand at the Adelaide Remand Center in South Australia. Each inmate was administered the UCLA Loneliness Scale Revised, which purports to measure dissatisfaction and satisfaction with social relationships. They were also administered the Depression, Hopelessness, and Suicide Screening Form-03, a self-report questionnaire designed to measure depression, hopelessness, and prior and current indicators of risk for suicide in an offender population. The Multidimensional Scale of Perceived Social Support was used to assess perceptions of the adequacy of social support received from family, friends, and a significant other. Data on demographic characteristics were also collected. 1 table and 39 references