Background: Repetitive negative thinking has been identified as an important predictor of suicide ideation and suicidal behavior. Yet, only few studies have investigated the effect of suicide-specific rumination, i.e., repetitive thinking about death and/or suicide on suicide attempt history. On this background, the present study investigated, whether suicide-specific rumination differentiates between suicide attempters and suicide ideators, is predictive of suicide attempt history and mediates the association between suicide ideation and suicide attempts. Method: A total of 257 participants with a history of suicide ideation (55.6% female; Age M = 30.56, Age SD = 11.23, range: 18–73 years) completed online measures on suicidality, general and suicide-specific rumination. Results: Suicide-specific rumination differentiated suicide attempters from suicide ideators, predicted suicide attempt status (above age, gender, suicide ideation, general rumination) and fully mediated the association between suicide ideation and lifetime suicide attempts. Conclusion: Overall, though limited by the use of a non-clinical sample and a cross-sectional study design, the present results suggest that suicide-specific rumination might be a factor of central relevance in understanding transitions to suicidal behavior.