Introduction: It has been recognized that the attention deficit (AD) persists into adulthood in 50-70% of cases, however, there is little research on prevalence and impact on this age group. We propose to determine the prevalence of AD in Chilean medical students. Methods: We used demographic survey, Goldberg mental health questionnaire and ASRS v.1.1. scale. Results: 22.9% were positive for mental symptoms, and 31% was for AD measured with ASRS, compared with 7% of self-reported prior diagnosis of AD. There was no significant correlation between diagnosis of AD by ASRS scale with sex, age and place of origin, but if there was one with positive Goldberg, history of previous psychiatric diagnosis and previous diagnosis of AD. Discussion: The measurement of DA is probably biased by emotional variables derived from the high demand and the expectation of academic achievement of students. We think that the true prevalence of AD in medical students should be close to 7% reported by students and in line with international publications. This is the first Chilean study on this topic and it forces to raise other research modalities.