In spite of the relevance on diagnosis, therapeutic strategies and prevention of psychopathy of the accurate assessment of psychopathic traits in youngsters, in Argentina the internationally widespread specific instruments have not been validated. This research is aimed to the assessment of the reliability and aspects of the validity of the Argentinean version of the Hare Psychopathy Checklist: Youth Version. Thus, thirty institutionalized juvenile offenders were simultaneously assessed by two raters who produced independent and a consensus scores. The raters used information from the same multiple sources of information. The results support that the Argentinian version of the scale is a reliable, homogeneous instrument with high internal consistence. The Intraclass Correlation Coefficient for the total score was .98 and the Cronbach's Alpha Coefficient was 0.96. Findings also support concurrent and convergent validity of the scale using correlation measures with other criteria and measures relevant to the construct, such as the score of non-violent offenses (r = 0.55; p= 0.002), the score of violent-offenses (r = 0.48; p = 0.008); Impulsivity scale score (r = 0.44; p = 0.02) and the count of types of conduct problems (r = .65; p < 0,001).