The muscle specific ubiquitin E3 ligase MuRF1 has been implicated as a key regulator of muscle atrophy under a variety of conditions, such as during synthetic glucocorticoid treatment. FoxO class transcription factors have been proposed as important regulators of MuRF1 expression, but its regulation by glucocorticoids is not well understood. The MuRF1 promoter contains a near perfect, palindromic glucocorticoid response element (GRE) 200 base pairs upstream of the transcription start site. The GRE is highly conserved in the mouse, rat and human genes, along with a directly adjacent FoxO binding element (FBE). Transient transfection assays in HepG2 cells and C₂C₁₂ myotubes demonstrate that the MuRF1 promoter is responsive to both the dexamethasone-activated glucocorticoid receptor (GR) and FOXO1, while co-expression of GR and FOXO1 leads to a dramatic synergistic increase in reporter gene activity. Mutation of either the GRE or the FBE significantly impairs activation of the MuRF1 promoter. Consistent with these findings, DEX-induced up-regulation of MuRF1 is significantly attenuated in mice expressing a homodimerization deficient glucocorticoid receptor, despite no effect on the degree of muscle loss in these mice versus their wild-type counterparts. Finally, chromatin immunoprecipitation analysis reveals that both GR and FOXO1 bind to the endogenous MuRF1 promoter in C₂C₁₂ myotubes, and IGF-1 inhibition of dexamethasone-induced MuRF1 expression correlates with the loss of FOXO1 binding. These findings present new insights into the role of the GR and FOXO family of transcription factors in the transcriptional regulation of the MuRF1 gene, a direct target of the GR in skeletal muscle.