Our research examined short-term within-person effects of relationship and task conflict on angry mood and somatic complaints. We assumed that conflicts of both kinds would be prospectively related to both indicators of impaired well-being, that the effect of relationship conflict would be stronger than the effect of task conflict, and that the effect of relationship conflict would be stronger when task conflict is low than when it is high. We tested our hypotheses with a daily diary study with ratings made 3 times/day for 2 weeks, involving 131 participants. We found a prospective main effect of relationship conflict on angry mood, but not on somatic complaints. In contrast, controlling for relationship conflict, task conflict was unrelated to both angry mood and somatic complaints. Supporting our assumption, task conflict moderated the effect of relationship conflict. Relationship conflict had a prospective effect on angry mood and somatic complaints that lasted until the next day if, and only if, task conflict was low.