This study was designed to identify physiological correlates of unresolved anger and sadness, and the shift between these emotions, in a context similar to that of emotion-focused, experiential psychotherapy. Twenty-seven university students reporting unresolved anger toward an attachment figure were induced to experience and express unresolved anger and sadness. Simultaneously, their heart rate variability, finger temperature, and skin conductance levels were monitored. The sequence of emotion induction was counterbalanced. Sympathetic activation, as reflected by finger temperature, increased significantly from anger to sadness, but not from sadness to anger. A follow-up study (N = 36) of participants induced to experience and express either anger or sadness in both the 1st and 2nd inductions ruled out an Anger x Time interaction and a sadness-sadness effect, suggesting that the increase in sympathetic activation from anger to sadness was a function of the unique sequence of emotions. These findings represent a first step toward using physiological measures to capture shifts from unresolved anger to vulnerable primary emotions during a therapy-like task and provide evidence for the purported mechanism underlying unresolved anger.