Instability on the dark side? Factorial structure, measurement invariance and reliability of the Dirty Dozen Dark Triad in the general population of Lima. The dark triad of the personality is a complex measure composed of three traits such as Machiavellianism, psychopathy and narcissism that are associated with destructive behaviors to the interests of others. The Dirty Dozen Dark Triad (DDDT) scale was used to evaluate the dark triad. The present study seeks to analyze the internal structure, measurement invariance and reliability of DDDT scores. 320 people were recruited (64.1% women), the average age was 24.4 and 89.7% were single. Four measurement models were identified by means of confirmatory factor analysis; the measurement invariance was also evaluated, which did not show a significant deterioration for the group according to gender. In addition, congeneric and tau-equivalent models were implemented and the accuracy of the scores for all the factors was > .70. This DDDT version provides useful evidence at the psychometric level to be implemented with a screening instrument in the psychological evaluation.