AbstractNegative impact of a firm's environmental misconduct can spread to other firms under the same category due to stakeholders' categorization. Such problem implies a sociocognitive process that has yet to be explored. Therefore, this study extends the current literature by exploring how interfirm similarity affects the spillover effects through stakeholders' engagement. We propose that interfirm similarity can be perceived by stakeholders as a categorization standard, which can lead to their opposition to other firms. Spillover of misconduct is caused by the decreasing stakeholders' trust, wherein the negative effect is contingent upon stakeholders' perceptions. A questionnaire study is conducted to investigate how people resist an innocent firm in China when a chemistry firm experienced an explosion accident. Our findings confirm that interfirm similarity increases stakeholders' opposition to the innocent firm by decreasing their trust. However, the negative effect is alleviated when the innocent firm is perceived as highly environmentally responsible. Our work contributes to the crisis spillover literature and carries important implications for the management of innocent firms that may lose from an industry peer's misconduct.