Heart rate variability was compared in 20 subjects wearing multifunctionalfabric (experimental sessions) and cotton (control sessions) clothing. Anxiety, depression, fatigue, and stress levels were lower and emotional levels were higher during the experimental sessions than in the control sessions. Multifunctional fabrics reduced the low-frequency/high-frequency power ratio of heart rate variability. These results support the hypothesis that multifunctional fabrics increase cardiac parasympathetic tone. In addition, subjects had lower heart rates during the experimental sessions compared with controls, suggesting a stabilizing effect on the autonomic nervous system. In conclusion, multifunctional fabrics may act to stabilize both the autonomic nervous system and psychological state.