Background: In preparation for the 2021 Tokyo Olympic/Paralympic Games, the Japanese government assessed the risks of infectious disease outbreaks and identified necessary preparations. This present study reviewed efforts made during a previous measles epidemic and describes the roles of hospitals. Methods: This descriptive study investigated the records of 198 children with measles. All children were treated at a general hospital during the period from January 1997 through February 1998. We also examined the actions of pediatricians during and after a measles outbreak in the community. Results: Of the 198 children, 145 (73%) were hospitalized. The measles vaccination rate in the previous year was approximately 75%. Of the patients examined, 53% were younger than 2 years of age; mean age was 2.75 years. Pneumonia and gastroenteritis accounted for 46% and 30% of the complications, respectively. Issues requiring attention included the number of hospital beds located in a negative pressure room or private room with a window, the need for gamma globulin preparations with high measles antibody titers, the necessity of increasing vaccination opportunities, and extension of physician working hours. Conclusions: Visitors from other countries could cause measles outbreaks in Japan. Measures that might mitigate an outbreak were maintenance of high vaccination rates, ready availability of information on the location of negative pressure hospital rooms, knowledge of the status of the measle outbreak, and flexible medical staffing. There is a risk of measles outbreaks among infants and among those who do not have a measles antibody titer.