We study whether short selling affects corporate tax aggressiveness. Exploiting staggered short-sale deregulation in the Chinese stock market as a source of variation in market pressure and monitoring, our difference-in-differences estimates show that the introduction of a shortselling scheme significantly discourages pilot firms from engaging in aggressive tax avoidance, in contrast to the findings by Luo et al. (2020). We also find that the negative effect of short selling on tax aggressiveness is more pronounced for firms that have high advertising costs, high institutional holdings, and CEO duality, and are located in regions with weak tax law enforcement. We further reveal that short selling has an indirect effect on tax aggressiveness through the additional external pressure exerted by auditors, media, and financial analysts, and lastly, challenge the main analysis by Luo et al. (2020). Our evidence highlights the monitoring and disciplinary roles that short sellers play in determining the level of corporate tax aggressiveness.