Within the past decade mass spectrometry has undoubtedly consolidated its role as a major player in modern bioanalysis. Mass spectrometry of oligonucleotides is an evolving field that has not reached its culmination point yet, as many aspects of oligonucleotide dissociation in gas phase still need to be clarified. Research in our group is focused on the elucidation of the dissociation mechanisms of oligonucleotides and their analogs and on the characterization of metal–oligonucleotide complexes by tandem mass spectrometry in order to gain structural information. Here, we present the dissociation mechanism of RNA and an example for the characterization of metal–oligonucleotide complexes.