One explanation for the positive effect of state empathic concern on helping is that such other-focused feelings reduce helpers’ perceptions of their personal costs for helping. Results from an experiment (N = 186) supported these assumptions and showed further that self-focused feelings of personal distress, another form of affective empathy, were a positive predictor of perceived costs. Moreover, I examined whether the strength of the negative relationship between empathic concern and personal costs depends on two forms of perceived similarity between the helper and the target, person similarity and experience similarity. For this purpose, I manipulated person similarity by portraying the target as either similar or dissimilar with regard to essential characteristics, and assessed experience similarity by asking whether or not participants share the target’s negative experience. As predicted, the negative relationship between empathic concern and perceived personal costs was strongest when person similarity was high and experience similarity low.