During ischemia-reperfusion injury, brief pre-exposure to oxidative stress renders organs resistant to subsequent severe damage. NF-${kappa}B$ is a transcription factor that is involved in reperfusion-induced inflammatory and immune responses. The activity of NF-${kappa}B$ has been shown to be modulated by oxidative stress in various cell types through different pathways. We studied the effect of pre-exposure to oxidative stress on subsequent NF-${kappa}B$ activation in $TNF{alpha}$-stimulated HEK293 cells. The cells were transiently exposed to 0.5 mM $H_2O_2$ for 20 min, prior to stimulation with $TNF{alpha}$, and the subsequent expression of NF-${kappa}B$-dependent genes and the levels of NF-${kappa}B$ signaling molecules were measured. Pre-exposure to $H_2O_2$ significantly delayed the $TNF{alpha}$-induced expression of an NF-${kappa}B$ reporter gene and inflammatory proteins (intercellular adhesion molecule-1 and IL-$1{eta}$). The degradation of inhibitor of NF-${kappa}B$ ${alpha}$ ($I{kappa}B{alpha}$) and the nuclear translocation of NF-${kappa}B$ were also delayed by $H_2O_2$ treatment, whereas $I{kappa}B{alpha}$ phosphorylation and $I{kappa}B$ kinase activity were not changed. When we examined the ubiquitin/proteosome pathway in $H_2O_2$-treated cells, we could not detect significant changes in proteosomal peptidase activities, but we were able to detect a delay of $I{kappa}B{alpha}$ poly-ubiquitination. Our results suggest that transient exposure to oxidative stress temporally inhibits NF-${kappa}B$-dependent gene expression by suppressing the poly-ubiquitination of phosphorylated $I{kappa}B{alpha}$ in HEK293 cells.