In 2015, South Korea experienced the largest outbreak to date of the Middle East Respiratory Syndrome (MERS-CoV) outside the Middle East. Fears related to a potential spread of the disease led to an increased alert level as well as heightened media coverage in the neighboring Hong Kong. A cross-sectional survey (N = 533) among residents of Hong Kong was conducted to assess the relationships between the effects of outbreak-related mass media coverage, interpersonal communication, the perceived level of concern in one’s close environment, and the uptake of preventive measures. A serial multiple mediator model finds that interpersonal communication and higher perceived concern indirectly influence the effects of media coverage on the engagement in preventive actions. These results expand previous research on the mediating role of interpersonal communication and support assumptions about a modified two-step flow of communication in the context of a public health emergency.