This study examined whether a guided imagery exercise impacted perceived cognitive, physical, emotional, and behavioral stress and whether higher initial levels of cognitive and emotional symptoms of stress were associated with greater physiological benefits from the guided imagery exercise. Twenty-nine participants completed measures of perceived stress. Heart rate and coherence levels were measured before and at the end of a guided imagery exercise. Cognitive and emotional stress scores decreased. Lower initial levels of emotional, physical and behavioral symptoms of stress were associated with greater reductions in heart rate. Decreases in behavioral symptoms of stress were associated with improvements in coherence. In conclusion, guided imagery exercises reduce cognitive and emotional stress and may be most effective at reducing heart rate when levels of perceived stress are low.