Dengue virus (DENV) is an approximately 10.7-kb positive-sense RNA virus that circularizes via RNA-RNA interactions between sequences in the 5' and 3' terminal regions. Complementarity between the cyclization sequence (CS) and the upstream AUG region (UAR) has been shown to be necessary for viral replication. Here, we present the solution structure of the 5' end of DENV type 2 in the presence and absence of the 3' end. We demonstrate that hybridization between the 5' and 3' CSs is independent of the UAR while the 5' UAR-3' UAR hybridization is dependent upon the 5' CS-3' CS interaction.