Abstract: The incredible explosion of “knowledge production” in Biology in the past two decades has created a critical need for bioinformatic instruments able to manage data and facilitate their retrieval and analysis. Molecular sequences and biological data on nuclear mitochondrial genes and their products are publicly available from a wide variety of mitochondrial specialized databases. Some are species-specific, mainly human dedicated, others contain only few species and for most of them the only sequences data reported concern proteins. We have developed MitoRes database to collect and integrate information on nuclearly encoded proteins and genes targeting the mitochondrion for all metazoan species and to provide a flexible and efficient tool for the export of bio-sequences in support of researchers interested in functional characterization of gene, transcript and amino acid sequences related to biogenesis, metabolism and pathological dysfunctions of mitochondria.