The primary objective of this study was to examine the psychometric properties of a measure of anger/rage attacks—the Rage Outburst and Anger Rating Scale (ROARS)—in a sample of youth (n = 81, ages 7–17 years, 72.8 % male) receiving treatment at an outpatient pediatric psychiatric clinic. A trained rater completed the ROARS and Clinical Global Impression-Rage (CGI-Rage). Children completed the Spence Children’s Anxiety Scale for Children and Center for Epidemiological Studies Depression Scale. Parents completed the Spence Children’s Anxiety Scale for Parents. Internal consistency (α = .89), inter-rater reliability (κ = .94) and 1-week test–retest reliability (r = .72) were calculated for the ROARS. The ROARS was correlated with CGI-Rage (r = .68, ρ < .001), although not with parent- and child-rated anxiety symptoms or with child-rated depressive symptoms. Implications regarding clinical utility of the ROARS and directions for future research are discussed.