Sinovenous thrombosis describes thrombosis in one or more of the cerebral venous sinuses. The incidence of SVT in childhood appears to be highest during the neonatal period. Although plasma level of D-dimer has been shown to be sensitive for the diagnosis of deep vein thrombosis and pulmonary embolism in adult patients, there are few data about the relationship between sinovenous thrombosis and D-dimer levels in childhood, especially in the newborn period. The authors' aim in presenting this case report is to discuss the usefulness of plasma D-dimer measurements as a predictor of cerebral sinovenous thrombosis in the newborn.