The purpose of this study is to explore spectators' worries and attitudes during the COVID-19 pandemic and to compare them by age group. The survey was conducted with spectators at a home match for Victorina Himeji, a professional women's volleyball club in Japan. Two hundred and seventeen spectators rated their worries about becoming infected with COVID-19 after being in the arena as well as their attitudes during the COVID-19 pandemic. The results reveal that spectators visiting the arena had significant levels of worry related to the attendees (e.g., “Gathering crowds of people in the arena” and “Possibility that someone in the arena is infected with COVID-19”). Furthermore, younger people were more worried about COVID-19 infection than other age groups, although no significant difference in attitudes appeared among the age groups. The findings of this study suggest the importance of practicing social distancing in the arena as well as measuring spectators' body temperature before they enter the arena. Furthermore, sport event organizers may need to implement the strategy of infection prevention based on spectators' age groups and other personal attributes.