The extent of fragmentation of molecules ionized from the solid state by static and dynamic secondary ion mass spectrometry increases as the translational energy of the bombarding Ar + or Cs + ion is decreased. This result applies to both positive and negative ions in the compounds examined, which include ammonium, arsonium, phosphonium, pyridinium, and sulfonate salts, as well as two neutral compounds, a polynuclear aromatic hydrocarbon, and an aromatic carboxylic acid. The degree of fragmentation also depends on the nature of the substrate, with copper consistently yielding more fragmentation than does silver, platinum, or gold. Fragmentation can also be increased by sputter deposition of a thin metal coating over the organic compound. Each of these effects is accounted for in terms of enhanced unimolecular dissociation due to increased internal energy deposition in the desorbed organic ions.