The coronavirus disease 2019 (COVID-19) has rapidly swept the world. Patients with cancer could be at particular risk of COVID-19, since they are often immunosuppressed by their therapy. Assessing the risk-benefit ratio of potentially immunosuppressive treatment for patients with cancer with insufficient knowledge of this new disease and balancing individual and community benefits poses acute ethical dilemmas for oncologists. Researchers provided the first guidelines for cancer patients treatment. Individual treatment plans should be adjusted to minimise routine visits, procedures and tests. Patients should be categorised into different priorities for receiving active cancer therapy during the pandemic. Oncologists should consider changing intravenous treatments to subcutaneous or oral routes, as well as suspending radiation therapy or using hypofractionation. In case of developing COVID-19 patients with cancer should be treated in the respiratory or intensive care units rather than in the oncology units. Preventive measures and emergency plans to help patients should also be developed. The COVID-19 pandemic has had a devastating impact on clinical research in haematology and oncology. A dramatic reduction in the number of participants in current research and delays in planned haematology and oncology research, as well as adverse financial consequences and potential delays in the delivery of promising drugs to patients should be expected. Regulatory agencies provided guidelines on managing clinical trials during the COVID-19 pandemic, emphasising the importance of pragmatism and flexibility in routine visits, procedures and tumour assessments and clearly documenting protocol deviations. Ensuring patients’ safety during the pandemic is of primary priority. Every trial participant should be contacted before the planned visit to ensure they don’t have any COVID-19 symptoms. Laboratory and radiological assessments should be done at the closest to patient medical facility, and some investigational products, such as oral medications, should be delivered directly to patient to avoid hospital visits. The COVID-19 pandemic has had a serious negative impact on both treatment of cancer patients and research in this area. The support of all stakeholders is the only thing that can help ensure the best possible care for patients at this difficult time.