The Oct-2 transcription factor has a predominantly inhibitory effect on gene expression in neuronal cell lines. This factor and its corresponding mRNA have previously been shown to be elevated in adult rat dorsal root ganglion (DRG) neurons chronically exposed to nerve growth factor (NGF). Here we show that the Oct-2 mRNA is rapidly induced in DRG cells exposed to NGF and that such induction still occurs to a lesser extent in the presence of the protein synthesis inhibitor cycloheximide. These findings characterize Oct-2 as a novel member of the immediate-early class of NGF-induced transcription factors whose previously defined members have a predominantly stimulatory effect on the expression of other genes. Induction of the Oct-2 mRNA was also observed in DRG neurons treated with acidic fibroblast growth factor or epidermal growth factor but not with a range of other growth factors and neurotrophins. The role of the Oct-2 transcription factor in mediating the response of DRG neurons to NGF is discussed.