Introduction: We report two cases of infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients treated by the palliative care team during the first wave of the coronavirus disease 2019 (COVID-19) pandemic. These patients were receiving interventions for pain control, but subsequently contracted COVID-19, leading to their deaths. Cases: Two patients with hematopoietic tumors had been taking hydromorphone tablets for pain control. Both patients contracted COVID-19 during their clinical course, and displayed happy hypoxia, a typical complication of SARS-CoV-2 infection. Although the rapid systemic deterioration of the patients' conditions were recognized, there were no complaints of breathing difficulties. We attempted to alleviate the symptoms by adjusting the medications, including changes to the administration route. Discussion: When a patient receiving palliative care is infected with SARS-CoV-2, the presence of an underlying condition may cause a rapid deterioration, and opioid titration may be required depending on the characteristics of the symptoms.