Child maltreatment has emerged as an important risk factor for substance use. However, despite evidence consistently demonstrating that substance use peaks during emerging adulthood, less is known about the specificity of maltreatment effects on substance use during this critical developmental period. Further, the factors that might play a role in these associations are not well understood. The current study examined the associations between child maltreatment types (i.e., physical abuse, physical neglect, sexual abuse, emotional abuse, and emotional neglect) and past month marijuana, alcohol, and tobacco use among emerging adults, and tested whether impulsivity accounted for these associations. Participants were 500 emerging adults ranging in age between 18 and 25 years old (M = 18.96, SD = 1.22, 49.6% male) recruited from a large, public university in the Midwest United States. Tests of indirect effects suggested that impulsivity accounted for associations between emotional abuse and past month marijuana, alcohol, and tobacco use. Current findings provide support for impulsivity as a mechanism linking childhood emotional abuse to substance use among emerging adults, highlighting the need for targeted screening and intervention.