Cardiovascular issues are important concerns in malignant lymphoma treatment. These issues can be broadly categorized into two groups: the invasion of malignant lymphoma into the heart and cardiovascular disease related to malignant lymphoma treatment. In terms of malignant lymphoma invasion of the heart, the presence of a heart lesion of malignant lymphoma often presents with heart-related symptoms and findings such as chest pain, heart failure, and arrhythmias. Notably, heart failure and arrhythmias can be fatal. The identification of heart lesions of malignant lymphoma will result in appropriate management and survival improvement. As for cardiovascular disease associated with malignant lymphoma treatment, the incidence and types of cardiovascular disease, management, and follow-up planning should be identified before starting treatment. This identification and plan will allow an understanding of the risk of developing cardiovascular disease and appropriate management and follow-up. In clinical practice, it is important to keep in mind that cardiac issues in patients with malignant lymphoma should be identified, assessed, and managed before initiating treatment.