Objective This study examined the relationship between explicit and implicit measures of hopelessness and self-injurious behavior (defined here as self-harming or suicidal actions and thoughts). Method A community sample of 267 participants completed explicit measures of hopelessness (Beck's Hopelessness Scale and a Feeling Thermometer), an implicit measure of hopelessness (Hopelessness Implicit Association Test), and a self-report measure of their history of self-injurious behavior. Results The results showed that high levels of hopelessness, measured both explicitly or implicitly, were associated with a past and recent history of self-injury. However, there was also an interaction between the implicit and explicit measures such that explicit hopelessness was more strongly predictive of self-injury in people with high levels of implicit hopelessness. Conclusion The findings show that the implicit measurement of hopelessness can help predict past and recent self-injury beyond what explicit measures of hopelessness currently achieve and could be used in the assessment of risk of both self-harming and suicidal behaviors.