Objective: to compare the effect of exposure to unpleasant odors in a simulated clinical environment on the emotions of undergraduate nursing students. Method: quasi-experimental study. A total of 24 nursing students participated the study, divided into two groups, 12 in the intervention group with exposure to unpleasant odors, and 12 in the control group without exposure to unpleasant odors. To simulate the unpleasant vomiting odor in intervention group, fermented foods were used: boiled oats, curdled milk, spoiled Parmesan cheese, raw egg, pea soup, raisins and vinegar. Participants were filmed and the facial expression analysis was performed at six critical points: student approach; report of the complaint; clinical evaluation; and patient occurrence, intervention and reevaluation based on what was proposed by the Circumplex model of emotions recognition. Results: a total of 83,215 emotions related to the six critical points were verified. At the critical point of the proposed scenario with exposure to unpleasant odors, the intervention group presented the basic emotion of sadness and the Control Group, anger. Conclusion: it is inferred that the inclusion of unpleasant odors in the simulated scenarios can broaden the emotional development of health students.