The coincidence of trisomy 21 and a structural rearrangement is very rare, and even it has not been reported as a prenatal diagnosis yet. In this article, we present an autosomal translocation carrier fetus with trisomy 21: 47,XX,+21, t(3;8)(p21;q24). Although the coincidence of reciprocal translocation and trisomy may be seen in reciprocal translocation carrier families, de novo cases are extremely rare. The presented case is diagnosed by amniocentesis, which was performed because of abnormal fetal ultrasonographic findings and increased trisomy 21 risk at maternal serum screening test. The postmortem pathologic examination of the fetus revealed that the findings of hypertelorism and right lung with two lobes are interesting novel findings of our cases associated with the breakpoints 3p21 and 8q24.