We report the development and psychometric evaluations of a self-report instrument designed to screen for psychopathic traits among mainstream community adolescents. Tests of item functioning were initially conducted with 26 adolescents. In a second study the new instrument was administered to 150 high school adolescents, 73 of who had school records of suspension for antisocial behavior. Exploratory factor analysis yielded a 4-factor structure (Impulsivity [alpha] = 0.73, Self-Centredness [alpha] = 0.70, Callous-Unemotional [alpha] = 0.69, and Manipulativeness [alpha] = 0.83). In a third study involving 328 high school adolescents, 130 with records of suspension for antisocial behavior, competing measurement models were evaluated using confirmatory factor analysis. The superiority of a measurement model represented by four correlated factors was supported, and this model was invariant across gender and age. The findings provide researchers and clinicians with a psychometrically strong, self-report instrument and a greater understanding of psychopathic traits in mainstream adolescents.