A prominent role for mitochondrial genes and metabolism has been recently characterized in oncocytic transformation of cancer cells. From mitochondrial ultrastructure alterations to respiratory complexes disruption and mutations within mitochondrial genes, oncocytic tumors present with a plethora of features that have helped understand the role that these organelles and their fundamental metabolic functions may play in cancer development. The history of this under-diagnosed subset of tumors and the bioenergetic implications of their mitochondrial derangement are discussed in this review along with the opportunities that oncocytic tumors offer to draw general conclusions on the involvement of mitochondria in cancer.