We employed a multi-informant approach to examine attention deficit hyperactivity disorder (ADHD) subtype differences, as well as ADHD versus comparison group differences, in overt aggression, relational aggression, and peer regard related to such aggression. Participants included 228 girls (ages 6 to 12 years) diagnosed with either ADHD-Combined (ADHD-C; n = 93), ADHD-Inattentive (ADHD-I; n = 47), or nondiagnosed comparisons (n = 88) who attended research-based summer camp programs. Girls with ADHD-C exhibited higher rates of overt and relational aggression than did girls with ADHD-I, who in turn exhibited higher rates than comparison girls. For the ADHD-C subgroup, aggressive behavior was associated with both negative peer regard and lack of positive peer regard; for the ADHD-I subgroup, aggressive behavior was related to negative peer regard but not to positive peer regard. Controlling for subtype, relational aggression contributed incremental variance in peer regard over and above overt aggression, but effects for the latter were stronger. We discuss the importance of overt versus relational aggression for girls with ADHD as well as disparities in findings according to informant sources.