DNA microarray studies offer a robust method for nonbiased analysis of whole genome messenger ribonucleic acid expression patterns. A growing number of studies have applied this experimental approach to studies on ethanol either in cell culture of animal models of ethanol exposure or self-administration. Expression profiling has identified novel gene networks responding to ethanol or differing across animal strains with differing responses to ethanol. Recent studies have shown benefit for meta-analysis of microarray data across different laboratories. Gene network analysis offers unique opportunities for understanding the molecular mechanisms of ethanol responses, toxicity and addiction. Eventually, such work may generate novel targets for future pharmacotherapy. To fully capitalize on the prom ise alluded to above, particularly in regard to meta-analysis of microarray data, it is critical that high quality standards are followed in the generation and analysis of microarray studies. This chapter will discuss experience of our laboratory in performing and analyzing microarray studies on ethanol, focusing discussion mainly on short oligonucleotide microarrays (Affymetrix). However, the general principals of technique and analysis that are discussed have broad applicability to other types of microarray platforms and experimental designs.