Congenital toxoplasmosis (CT) and cytomegalovirus infection (cCMV) may cause significant morbidity and even fetal or neonatal mortality. We aimed to quantify the disease burden of CT and cCMV in Belgium in terms of disability-adjusted life years (DALYs) and identify data gaps. The public health impact of CT and cCMV in Belgium in 2013 was 188 (95% uncertainty interval [UI], 43-419) and 1976 (95% UI, 757-4067) DALYs, respectively. The major data gaps identified were representative Belgian studies; information on important sequelae, intrauterine mortality, and termination of pregnancy; and late onset sequelae. A scenario analysis showed important increases in years of life lost when the burden due to fetal losses was included and decreases in DALYs when comprehensive CT prevention measures were conducted. Addressing the key data gaps identified may allow generation of the data needed to break the vicious circle of underrecognition.