<p>The COVID-19 pandemic has generated various consequences on mental health, unleashing an underlying epidemic that affects all social strata. In this sense, the present study aimed to evaluate the effect of an online mindfulness program on levels of academic stress, anxiety and depression in health science students during times of COVID-19; to get this purpose an experimental design study was carried out with pretest and posttest measurements, in a sample of 78 students, divided into an experimental group whose members were administered with an online mindfulness program of 12 sessions, and a group control on waiting list. The SISCO inventory was used to measure academic stress, the STAI questionnaire for state anxiety and trait anxiety; as well as the Zung depression scale was used. The levels of academic stress, anxiety and depression decreased after the intervention, finding significant differences between the groups and study phases (p &lt;0.05). Besides It was found moderate changes in academic stress (d = 0.55), stressors (d = 0.86), symptoms (d = 0.52), trait anxiety (d = 0.59) and depression (d = 0.72); and important changes in coping strategies (d = 1.11) and state anxiety (d = 1.16).</p>