Congenital aneurysm of the ductus arteriosus is reported in 0.8% in neonatal autopsies, however true incidence is unknown because of high rate of asymptomatic cases and spontaneous regression. Possible complications in symptomatic cases are; thromboembolism, spontaneous rupture, erosion, infection, compression of airways and death. In this report we present a newborn with giant DAA diagnosed in first day of life, surgically treated after thrombosis of aneurysm.