Rumination has been previously linked to negative psychological outcomes, including depression and suicidal behavior. However, there has been conflicting research on whether or not two different subtypes of rumination – brooding and reflection – are more or less maladaptive. The present research sought to (1) examine whether individuals high in brooding but lower in reflection would show higher trait and behavioral impulsivity, relative to individuals low in brooding and low in reflection; and (2) examine impulsivity as a mediator of the relation between ruminative subtypes and suicidal ideation. In Study 1, participants (N=78) were recruited based on high, average, and low scores on a measure of brooding and reflective rumination. Individuals who scored high in brooding and average in reflection scored significantly higher in negative urgency, that is, in the tendency to act rashly in an attempt to reduce negative affect, than did those who scored low in brooding and low in reflection. Study 2 (N=1638) examined the relationship between ruminative subtypes, impulsivity, and suicide risk. We found an indirect relationship between brooding and suicide risk through lack of premeditation and lack of perseverance, independently of reflection. These findings are discussed in relation to cognitive risk for suicide.