The COVID-19 pandemic has had a multifaceted impact on cancer patients. This chapter focuses on the haematological effects of the SARS-CoV-2 virus on cancer patients. Three major haematological complications which commonly arose for cancer patients over the course of the pandemic will be discussed: thromboembolism, cytokine release syndrome and coagulopathies. Additionally, the challenges faced by all healthcare systems in providing uninterrupted cancer treatments will be discussed. The haematological implications of the mental health burden experienced by cancer patients are also addressed, highlighting the need for comprehensive psychological support. Overall, the chapter underscores the importance of tailored approaches to effectively recognise and manage the haematological complications of COVID-19 infection.