The communication of chemosensory alarm signals is well explored in mammals. In humans the effects of anxiety substances mightseem to be less important due to their high-developed visual system, and their sophisticated ability to communicate via speech and bodylanguage. Nevertheless, an increasing number of studies suggest an effect of chemosignals of anxiety on human physiology and behavior. In thepresent study two kinds of human sweat were collected from 21 males during a bicycle workout and a visit of a high rope course, and were thenapplied to 15 different healthy male participants during an emotion evaluation task. Participants were instructed to rate emotional male faces ofdifferent morphing levels (neutral-happy) by using a visual analog scale under exposure of three different samples (exercise sweat, anxiety sweat,and control material). Our study revealed that men rated happy faces as less happy under the influence of anxiety sweat compared to the exerciseand the control conditions; significant differences were demonstrated only for ambiguous emotional faces. In conclusion, chemosignals of anxietycomprised in human sweat are communicated between males; they diminish the evaluation of ambiguous happy male facial expressions in menand thereby influence the perception of emotional faces.