Room temperature ionic liquids (ILs) have many applications including as matrices in MALDI. We wished to investigate the efficacy of ILs as matrices in time-of-flight secondary ion mass spectrometry and in mass spectrometric imaging (MS imaging). Two ILs derived from alpha-cyano-4-hydroxycinnamic acid (CHCA) were synthesized and tested using phospholipids, cholesterol, and peptides. The molecular ion intensities of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), cholesterol, and bradykinin were greatly increased using IL matrices. Further, detection limits were also improved: for DPPC and DPPE detection, limits were at least 2 orders of magnitude better using IL matrices. However, these IL matrices were not effective for the enhancement of angiotensin I ions. The data also indicate that IL matrices are suitable for imaging MS. The IL matrices did not cause changes to the sample surface via matrix crystallization or other processes; no "hot spots" were observed in the mass spectra. As a demonstration, an onionskin membrane was imaged. In the matrix-enhanced MS images, ions characteristic of proteins and other biomolecules were observed which could not otherwise be observed. Clearly ionic liquids deserve further investigation in SIMS and MS imaging.