This review summarizes the known data about transcriptional control of the tumor necrosis factor genes. Mechanisms of transcriptional induction of TNF gene expression and the influences of regulatory elements in the promter and in the 3' flanking regions are discussed. Posttranscriptional events that influence regulation of TNF gene expression such as destabilization of mRNA are described. The influence of chromatin structure and possible functional implications are also reported. Although their biological effects largely overlap, it is concluded that the TNFα and TNFβ genes are differently regulated at the transcriptional level.