Despite improved survival rates, childhood and young adult (YA) cancer survivors face elevated risks for life-threatening morbidities, especially cardiovascular complications. Our nationwide Finnish registry study investigated the purchases of cardiovascular medication from 1993 to 2011 in patients diagnosed with cancer aged below 35 years (N=8,197) between 1993 and 2004 compared to siblings (N=29,974) via linkage to the drug purchase registry. The cumulative incidence for purchasing cardiovascular medications was higher in childhood and YA cancer patients compared to siblings with a rising trend over time. After childhood cancer, the highest HR was found for purchasing anticoagulants (HR 19.8, 95%CI 8.5-45.9). The HRs for any cardiovascular medication (HR 7.2, 95% CI 5.1-10.1) and cardiac medication (HR 4.8, 95% CI 3.3-6.9) were markedly elevated after childhood cancer as well. Regarding YA cancer patients, the respective HRs were 2.5 (95%CI 2.0-3.2) for anticoagulants, HR 1.7 (95% CI 1.5-1.9) for any cardiovascular medication, and HR 1.5 (95%CI 1.3-1.7) for cardiac medication. Among cancer patients, highest HRs for cardiovascular medication were observed after childhood acute lymphoblastic leukemia (ALL) and bone tumors (HR 10.2, 95% CI 6.8-15.5 and HR 7.4, 95% CI 4.0-13.7) and YA ALL and acute myeloid leukemia (AML) (HR 5.1, 95% CI 3.5-7.1 and HR 2.8, 95% CI 1.8-4.0). Our study demonstrated increased HRs for purchasing cardiovascular medication after early onset cancer compared to siblings reflecting elevated cardiovascular morbidity. Thus, the implementation of long-term cardiovascular disease screening is imperative to prevent, detect and adequately treat cardiovascular late effects after cancer at a young age.