Interpersonal offenses frequently mar relationships. Theorists have argued that the responses victims adopt toward their offenders have ramifications not only for their cognition, but also for their emotion, physiology, and health. This study examined the immediate emotional and physiological effects that occurred when participants (35 females, 36 males) rehearsed hurtful memories and nursed grudges (i.e., were unforgiving) compared with when they cultivated empathic perspective taking and imagined granting forgiveness (i.e., were forgiving) toward real-life offenders. Unforgiving thoughts prompted more aversive emotion, and significantly higher corrugator (brow) electromyogram (EMG), skin conductance, heart rate, and blood pressure changes from baseline. The EMG, skin conductance, and heart rate effects persisted after imagery into the recovery periods. Forgiving thoughts prompted greater perceived control and comparatively lower physiological stress responses. The results dovetail with the psychophysiology literature and suggest possible mechanisms through which chronic unforgiving responses may erode health whereas forgiving responses may enhance it.