We estimated Epstein-Barr virus (EBV) antibody-associated relative risks (RR) of malignant lymphoma/leukemia within a cohort of 39,000 healthy Finnish adults followed up for 12 years. Antibody analyses to EBV capsid antigen (VCA), early antigen (EA), and nuclear antigens (EBNA, EBNA1, and EBNA2) were based on concomitantly evaluated ELISA techniques. No increased risk was associated with mere EBV seropositivity. However, elevated EBV EA and EBNA antibody levels were associated with a statistically significant excess risk of malignant lymphoma/leukemia (RREA = 3.4, 95 percent confidence interval [CI] = 1.0-11.0; RREBNA = 4.5, CI = 1.2-16.9). These elevated antibody responses may be due either to destruction of neoplastic EBV positive B-cells and/or to activation of latent EBV infection early in the lymphomagenesis.