We report the complete mitochondrial genome of firefly, Pteroptyx maipo. The circular genome of 16,127 bp has a base composition of A (44.22%), C (11.60%), G (8.23%) and T (35.96%). Our sequence is similar to other Metazoa, which contains 13 protein-coding genes. All 13 protein-coding genes were initiated by the ATN (ATT, ATA and ATG) codon. Nine protein-coding genes stopped with TAA or TAG codon and the other four genes have an incomplete termination codon, a single T. We sequenced the mitochondrial genome of fireflies to analyze phylogenetic relationships and deduce the evolution of their flashing signals.