In this article, we analyze the internal consistency of the Diagnostic and Statistical Manual of Mental Disorders–5th ed. (DSM–5) diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD) in the adult population, in addition, we analyze the correlation between the teacher’s report and the student’s own, the prevalence of the disorder and the risk of presenting it according to gender. The sample was composed by 175 university students aged between 16 and 36 years old (M = 21.49, SD = 3.22) that belonged to the private higher education system of Quito, Ecuador. As measurement instruments, two scales were used based on the 18 items of the diagnostic criteria for ADHD described in the DSM–5. As a result, it was determined that the scales used present adequate internal consistency coefficients (attention deficit α = .77 & α = .90; hyperactivity/impulsivity α = .74 & α = .91 & the total scale α = .83 & α = .92 filled by the student and the professor, respectively), all scales correlated significantly between .15 and .88. As far as the ADHD prevalence percentage in university students, findings showed that the subtypes would be present between 7.42% and 26.85% of the time. As a risk factor, it was found that men present more probability to have ADHD than women. The article concludes pointing out the importance to implement intervention programs for university students that could present ADHD, since the condition could influence negatively the spheres in which the students with the disorder perform.