Individuals ostracize others for myriad reasons, yet the influence of those reasons on the psychological experience of ostracizing is yet unknown. Two studies aimed to determine the emotional and behavioral sequelae of ostracizing for different motives, directly comparing punitive to defensive motives. We focused our examination on a suite of emotions expected to arise as a function of (1) the situations that give rise to ostracizing for punitive and defensive reasons (anger, fear, anxiety, and sadness) and (2) the act of ostracizing itself (i.e., pride and guilt). The research employed a novel paradigm to induce the experience of ostracizing for defensive or punitive motives. Study 1 (N = 372) investigated sources' experienced emotion as a function of motive. Study 2 (N = 743) expanded consideration to behavioral intentions, including intentions to continue ostracizing and to recruit others to join in ostracizing the target. Across both studies and supported by an internal meta-analysis, ostracizing for defensive reasons was associated with higher levels of guilt, fear, and anxiety, and lower levels of anger, compared to ostracizing for punitive reasons. Neither sadness nor positive emotion (pride or happiness) differed significantly according to motive in either study. Moreover, guilt and anger mediated the impact of motive on intentions to continue ostracizing and recruit others to join them in ostracizing. To the extent that punitive sources experienced anger relative to defensive sources, they expressed greater intentions to continue ostracizing the target and to recruit others to join in ostracizing the target. To the extent that defensive sources experienced guilt relative to punitive sources, they reported reduced intentions to continue ostracizing the target. Findings add to a growing literature on ostracism sources, and highlight the mediating role of sources' emotion in guiding future actions.