Cigarette smoke has many toxic components that can lead to the disruption of various cellular processes. Increase in oxidative stress due to cigarette smoke causes production of reactive oxygen species, which induce vascular disease. 3-methylcholanthrene (3MC) is an environmental contaminant derived from the incomplete combustion of cigarette smoke and is one of the major polycyclic aromatic hydrocarbons. 3MC activates the aryl hydrocarbon receptor and contributes to carcinogenesis and vascular disease. The present study investigated gene expression in 3MC-treated human umbilical vein endothelial cells by microarray gene expression profiling. We found 1,279 and 717 genes with altered gene expression within 24 h of 100 nM and $1{mu}m$ 3MC treatment, respectively; these genes were distributed into distinct functional groups. Some of the genes including ICAM1, PTGS2, APOL3, and GPX-1, were related to cardiovascular disease. Our results support the hypothesis that 3MC-stimulated gene expression in endothelial cells may play a role in the development of cardiovascular disease.