Background: COVID-19 infection is a worldwide health threatening disease, especially for malignant tumor patients. Systemic antitumor therapies may slower the body to clear virus, which results in delayed recovery from COVID-19. Thus, present guidelines or expert consensuses recommend to postpone antictumor therapies, which would unquestionablely retard treatment cycle and reduce therapeutic effect.Gemcitabine is a nucleoside analogue, which has shown antiviral activity as well as anticancer effect. Therefore, we assume that antitumor regimens with gemcitabine are also able to control COVID-19 reproduction. Such “kill two birds with one stone” regimen aims to not delay both anticancer treatment and COVID-19 turning negative. Methods: Four newly pathologically diagnosed advanced tumor patients from Department of Oncology, Second Xiangya Hospital, Central South University were collected, including three nasopharyngeal carcinoma (NPC) patients and one non-small cell lung cancer (NSCLC) patient. All of them were asymptomaticly infected with COVID-19 recently. Anticancer regimens with gemcitabine were adopted as initial treatment for these patiens. Three patients with NPC received gemcitabine combined with cisplatin (gemcitabine 1g/㎡ on day 1 and 8, cisplatin 25mg/㎡ from day 1 to 3).The patient with NSCLC accepted gemcitabine and PD-1 inhibitor (gemcitabine 1g/㎡ on day 1 and 8,tislelizumab 100mg on day 1 and 8). Throat swabs were performed to test the COVID-19 nucleic acid on day 1, 5, 9 and 21 during treatment. Results: Four patients are all middle-aged males of 43-59 years old. Their COVID-19 nucleic acid tests were positive on day 1 before infusing any drugs.The cycle count threshold (CT) of nucleic acid did not go down but gradually went up during antitumor treatment.Patients showed no COVID-19 related symptom during the whole treatment cycle. There were no greater than or equal to grade 3 adverse evens (AEs). Treatment related AEs included one patient with grade 2 leukopenia, and one patient with grade 2 fever. All patients normally finished the first anticancer cycle and successfully went to the second cycle. Conclusions: Antitumor regimens with gemcitabine is safe for patients both with manignancy and COVID-19. Cancer patients with COVID-19 can accept gemcitabine-related therapy as soon as possible intead of waiting until COVID-19 nucleic acid becoming negative.