Sin firms often face negative public opinion, adverse media coverage, and stringent regulatory scrutiny due to their controversial product offerings, which may compel them to adapt their disclosure strategies to minimize political cost exposure. Although prior studies indicate that sin firms are more likely to issue standalone CSR reports to enhance their legitimacy, it is still unclear whether their voluntary financial disclosure behaviors differ from those of non-sin firms. We provide evidence that managers of sin firms are less likely to provide non-GAAP earnings disclosure compared to matched non-sin counterparts. Our cross-sectional analyses reveal that the negative effect of sin firm status on non-GAAP disclosure is mitigated in sin firms with political connections but more pronounced when such firms receive more media coverage. Our findings are robust against exogenous experiments, alternative explanations, and different empirical specifications. Further analyses show that managers of sin firms are more likely to disclose non-GAAP earnings that are less profitable than their GAAP counterparts, exclude fewer persistent expenses in calculating these earnings, and that the non-GAAP earnings disclosed by sin firms are of higher quality. Overall, this paper concludes that political cost considerations shape the corporate non-GAAP disclosure decision of sin firms.