The advent of microarrays in studying gene expression in aging has created tremendous excitement due to its potential for uncovering molecular mechanisms of aging and age-related disease. However, the appropriate implementation of this technology in the science of aging requires serious attention to methodological detail and statistical rigor. This report highlights discussions from the microarray workshop on aging held at the First Conference on Functional Genomics of Aging in Seville, Spain. The topics discussed by the participants included technical issues relating to the printing of arrays, RNA isolation, cDNA labeling and hybridization, optimal design of microarray experiments, and statistical analysis of these data. Microarray analysis of complex tissues through the use of laser capture microdissection was also discussed.