Purpose <p>The Death-Implicit Association Test (D-IAT) was developed to assess implicit cognitions that may indicate a bias towards suicide or death. Although the D-IAT is widely used, little is known about its prospective validity. The current study assessed the prospective validity and treatment sensitivity of the D-IAT in a large sample of inpatients at high risk of suicide. We hypothesized that baseline D-IAT scores would (a) improve from pre- to post- inpatient admission, reflecting a stronger association between self and life; and (b) predict suicidal thoughts and behaviors across a 6-month follow-up period post-discharge.</p> Methods <p>Participants were 200 individuals admitted to the psychiatric inpatient unit for suicide risk. They were randomly assigned to receive inpatient treatment as usual (TAU) or brief cognitive-behavioral therapy for suicide prevention (BCBT) and completed the D-IAT before and after treatment and monthly for six months after discharge.</p> Results <p>Contrary to our hypotheses, D-IAT scores did not significantly change from pre- to post-admission and did not predict suicidal thoughts or behaviors across the follow-up period, with the exception of aborted attempts.</p> Conclusions <p>The findings largely do not support the prospective validity of the D-IAT nor its sensitivity to detect treatment effects, although replication in samples with greater frequency of suicidal behaviors across the follow-up period will be needed.</p>