Following the sequencing of the human and other genomes, much research effort is now invested in post- genomic science, particularly in the related disciplines of proteomics and metabolomics. In this paper, we will attempt to provide an overview of mass spectrometry-based metabolomic strategies, discuss the evolution of metabolomics from its predecessor, Hmetabolite profiling", and provide some pointers to future methodological and technological direction. Current data from the authors' laboratory will also be presented, highlighting our efforts in the field of "targeted metabolomics", namely, "steroidomics in the brain".