In this study, different first-order and bifactor models of attention deficit hyperactivity disorder (ADHD) have been tested using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM). Nine models were estimated for a sample of 871 children (465 males and 406 females) aged between five and fourteen years old through a scale constructed with the 18 ADHD symptoms proposed in the DSM-5, completed by parents and teachers. The models were divided into five first-order models (CFA and ESEM) and four bifactor models (Bi-CFA y Bi-ESEM). The results indicated that both Bi-ESEM models show a better fit over the rest, with three specific factors showing the best fit with a strongly defined G factor.