Non-suicidal self-injury and suicidal behavior are prevalent in young adults, and often constitute a continuum of self-destructiveness. Not all those who self-injure, however, engage in suicidal behaviors with intent to die, perhaps due to protective intrapersonal characteristics. We examined the role of one such potential buffer, social problem-solving ability, as a moderator of the association between non-suicidal self-injury and suicidal thoughts and attempts, hypothesizing that individuals with greater social problem-solving ability would report fewer suicidal behaviors in relation to self-harm. An ethnically diverse sample was recruited from a large, Northeastern urban university, and completed self-report questionnaires assessing non-suicidal self-injury, suicidal behaviors, and social problem-solving ability. Multivariate hierarchical regression analyses were conducted. For the entire sample, individuals with higher social problem-solving abilities reported fewer suicidal behaviors associated with non-suicidal self-injury. In ethnically stratified analyses, social problem-solving significantly moderated the relationship between self-injury and suicidal behaviors for Whites and Hispanics only. Promotion of problem-solving skills may weaken the linkage between self-injury and potential for future suicidal behaviors for some individuals; however, culture-specific differences in this effect may exist.