On March 1, 2020, the Central Epidemic Command Center (CECC) announced the 40th confirmed case of coronavirus disease 2019 (COVID-19) in Taiwan. Case #40 is a female in her 70s who resides in northern Taiwan. She was a passenger aboard Diamond Princess cruise liner, and was admitted to a hospital in Japan after she tested positive for COVID-19. After her preliminary and confirmatory tests came back negative February 25, Case #40 was discharged from the hospital. She returned to Taiwan by plane February 26. During her flight, she had worn a face mask, and no passengers had been seated in the same row, and two rows in front of and behind her. Upon her arrival in Taiwan, she also went through entry quarantine procedure with the help of responsible agencies. She was then sent to a hospital on an ambulance for further quarantine and lab tests. Case #40 tested for COVID-19 three times and was diagnosed with the novel coronavirus March 1. People having contact with Case #40 after she returned to Taiwan had used protective equipment. Thus, these contacts are not required to test for COVID-19.