Ethical attributes (i.e., product attributes that reflect social and environmental issues) do not always increase product evaluations and choice. This article examines whether ethical attributes differentially affect evaluations of retailers’ private label brands (PLBs) and manufacturers’ national brands (NBs). Two experiments show that ethical attributes enhance consumer evaluations of PLBs (but not NBs) in the presence of extrinsic cues signalling high quality (i.e., high price). In the context of extrinsic cues signalling low quality, (i.e., low price), an ethical attribute hurts PLB (but not NB) evaluations. This effect is mediated by consumers’ product quality perceptions. A third experiment replicates these effects of ethical attribute presence on PLB evaluations in the context of retailer reputation serving as an extrinsic cue, and shows a moderating effect of consumers’ resource synergy beliefs. Overall, these results suggest that PLBs benefit from offering ethical attributes in the context of higher-priced PLBs or higher retailer reputation.