It is becoming clear that mass spectrometry is a powerful tool for the analysis and imaging of complex organic and biological systems. The discussion session "Meeting the Challenge of Molecule Specific Analysis and Imaging in Organic and Bio-Systems" will attempt to illustrate the challenges to be met in mass spectral imaging and analysis of biological samples. Some of these challenges will be discussed here including the issues of sensitivity needed to obtain high resolution images at the cellular and sub-cellular level, information that can be obtained with alternative techniques and where will they be better versus when SIMS will be better suited to the need, and finally the need for depth profiling and mechanisms to achieve this goal for cellular samples. (c) 2006 Elsevier B.V. All rights reserved.