In this study, mRNA profiles generated from cDNA microarrays were used to identify gene expression changes in Arabidopsis thaliana ecotype Shahdara infected with Tobacco mosaic virus (TMV). Shahdara is a susceptible TMV host, permitting rapid accumulations of virus in both inoculated and systemic tissues, accompanied by defined disease symptoms that include stunting, necrosis, and leaf curling. Gene expression profiles were monitored in whole tissues of inoculated leaves at four days postinoculation (dpi) and in systemically infected leaves at 14 dpi. Microarrays contained cDNAs representing between 8,000 and 10,000 Arabidopsis genes. Expression analysis identified 68 genes that displayed significant and consistent changes in expression levels, either up or down, in either TMV inoculated or systemically infected tissues, or both. Identified TMV-responsive genes encode a diverse array of functional proteins that include transcription factors, antioxidants, metabolic enzymes, and transporters. Thus, the TMV infection process has a significant impact on a wide array of cellular processes that likely reflect the biochemical and physiological changes involved in the development of this disease syndrome.