Mitochondria have their own gene expression machinery and the relative abundance of RNA products in these organelles in animals is mostly dictated by their rate of degradation. The molecular mechanisms regulating the differential accumulation of the transcripts in this organelle remain largely elusive. Here, we summarize the present knowledge of how RNA is degraded in human mitochondria and describe the coexistence of stable poly(A) tails and the nonabundant tails, which have been suggested to play a role in the RNA degradation process.