Objective: Development of severe disease and death from COVID-19 is more frequent in patients with comorbidities. Some studies report an increased frequency of severe COVID-19 in cancer patients. This review aims to describe the risk of infection and developing severe COVID-19 in cancer patients. Materials and methods: A systematic review was carried out through an exhaustive search of literature in PubMed and Scopus until May 2020. A secondary search was performed to include more studies. Results: The initial search identified 2,192 records, which included 17 publications with at least 10 infected cancer patients. Also, 5 articles were added from the additional search of the references cited by those 17 publications. Ten publications were from Chinese authors. Data analysis showed that COVID-19 infection is more frequent in cancer patients, and frequent therapeutic visits to the healthcare facility may be the cause. The presence of neoplasia predisposed patients to develop severe disease. Advanced age, associated comorbidities, advanced malignancy, and the presence of serum inflammatory markers increased the risk of developing severe disease. Initial studies indicate that the use of systemic treatment may also be a predisposing factor. Conclusions: The risk of becoming infected by COVID-19 and developing severe disease is higher in the oncological population.