Context Quantitative changes of salivary proteins due to acute stress were detected. Objective To explore protein markers of stress in saliva of eight medical residents who performed emergency medicine simulations. Materials and methods Saliva was collected before the simulations, after the simulations, and following morning upon waking. Proteins were separated by SDS-PAGE, identified by MS, and relatively quantified by densitometry. Results Salivary alpha-amylase and S–type cystatins significantly increased, while the ~26 kDa and low-molecular weight (<10 kDa) SDS-PAGE bands exhibited changes after stress. Discussion and conclusion Alpha-amylase and cystatins are potential salivary markers of acute stress, but further validation should be performed using larger sample populations.