While information campaigns have been widely recognized as a pillar of public health crisis management and heightened by the current COVID-19 pandemic, an insufficient number of studies have investigated the impact of information disclosure on influencing citizen cooperation crucial for emergency management. Focusing on generic information disclosure practices during the recovery period from January 19, 2020, to February 29, 2020, in China and by employing a difference-in-difference method, this study finds that information disclosure significantly enhanced citizen coproduction as measured by aggregated search queries of COVID-19-related information, and earlier disclosure yielded greater effect more quickly. Moreover, government capacity and citizens' trust in government at the local level significantly moderate the positive impact of information disclosure. This study uncovers the novel relationship between information disclosure and citizen coproduction during emergencies in the Chinese context. Copyright © 2021 Wiley Periodicals LLC.