Abstract: Mass spectrometry (MS) imaging can provide near-micron-resolution maps of the elemental and molecular composition of mammalian tissue, microbial biofilms, electronic or medical devices, and other chemically complex structures. Matrix-assisted laser desorption ionization is perhaps the leading probe used in MS imaging. Complementing nanosecond laser desorption with laser postionization improves signals, minimizes differential detection, and facilitates analysis of electrically insulating samples. Replacing nanosecond laser desorption with <100 fs laser pulses for sample ablation promises submicron lateral resolution and depth profiling in MS imaging without any need for complex sample preparation schemes. This talk describes several strategies for improving laser-based MS imaging, with examples given in the analysis of microbial biofilms, pancreatic tissue, and geological samples.