The calliphorid genus Dyscritomyia is endemic to the Hawaiian Islands, and these flies provide another example of adaptive radiation within that archipelago. Dyscritomyia species have traditionally been considered members of the Tribe Luciliini, or greenbottle flies, although the exact systematic position of the genus has never been known. This is part of a larger problem in that the limits and systematic position of many calliphorid species are unclear, and the monophyly of the Calliphoridae itself is in dispute. As part of a larger investigation of calliphorid systematics, we performed a phylogenetic analysis of Dyscritomyia and members of the greenbottle genus Lucilia based on mitochondrial cytochrome oxidase (COI+II) sequence data. The resulting cladogram had ≥87% bootstrap support for all branches and it recovered the Lucilia species-groups that are supported by morphological criteria. Dyscritomyia was the sister lineage to Lucilia. Therefore it is unlikely that the Hawaiian genus evolved from any Lucilia species. Although these results are preliminary it appears that COI+II sequence data will provide a strong phylogenetic signal for any future investigation of Dyscritomyia and other greenbottle flies.