This review illustrates how a random observation at the laboratory bench has helped pave the way towards the development of organelle-targeted pharmaceutical nanocarriers. A fortuitous discovery in the mid 1990s involving the self-assembly of a molecule, known to accumulate inside mitochondria, has lead to the development of subcellular nanocarriers suited for the selective delivery of biologically active molecules to mitochondria inside living mammalian cells. Applications for mitochondria-specific drug and DNA delivery are described, the current state-of-the-art of mitochondrial drug targeting technology is reviewed, and its future perspectives are discussed.