Abstract: Suicide remains a significant clinical concern for military service members and veterans. One approach to reducing suicide risk has been to treat psychiatric disorders that are highly associated with suicide, such as posttraumatic stress disorder (PTSD). Much of the research on reducing suicide risk has focused on assessing suicidal ideation as a predictor of suicidal behavior, but suicidal ideation has consistently been identified as poor predictor of suicide or suicide attempts. Suicide cognitions have been proposed as an alternative to suicidal ideation when predicting suicide risk. In this study, we investigated whether suicide cognitions changed during PTSD treatment and whether those changes were associated with reductions in PTSD and depression severity. The study sample was comprised of 235 military service members and veterans who completed a two-week intensive treatment program for PTSD between April 2024 and May 2025. Results showed a large decrease in suicide cognitions after treatment (d = 0.82) and that these decreases were associated with reductions in PTSD severity (b = 0.59, p < .001). However, while lower suicide cognitions were associated with lower levels of depression (b = 0.12, p = .003), this association appeared to be only between-subjects, and not within-subjects over time (b = 0.02, p = .445). Lastly, reductions in suicide cognitions (b = 1.24, p < .001) predicted reductions in suicidal ideation over time. When taken together, these findings support the notion that PTSD treatments may reduce risk of suicide via decreases in suicide cognitions though more research is needed.