Abstract This study determined the first complete mitochondrial genome of a demoiselle, Vestalis melania (Odonata, Zygoptera, Calopterygidae) using long-range PCR and a primer walking approach. This mitogenome is 16,685 bp long and contains the entire set of 37 genes and an A þ T-rich control region typically found in insects. Presently, this mitogenome is the largest mitogenome of all available odonates, mainly because of its long A þ T-rich region (2036 bp). The gene arrangement of the V. melania mitogenome is identical to that of other known odonates. The inter-genic spacer s5 shared by the Anisoptera is absent in V. melania, which supports the view that the absence of the s5 spacer is a synapomorphy of the Zygoptera