The aim of this work is to examine the pentafactorial validity of the AF5 Self-Concept Questionnaire in Spanish and Chilean young adults. From the responses of a total of 4,383 young adults aged 17 to 22 years (1,918 Spanish, 44%, and 2,465 Chilean, 56%) it was analyzed the reliability of the instrument, the compared validity of the 5 oblique factor model proposed by the authors versus the unifactorial and the orthogonal alternative models, and was studied the invariance of one Chilean sample. The results of confirmatory factor analyses supported the authors' pentafactorial model. The multi-group factorial invariance showed that Chilean sample of the AF5 does not change neither the Spanish factor weights, nor the variances and covariances of the factors, or the error variances of items. Finally, the internal consistency of the five scales was good in the samples of both countries.