The experiments described herein were conducted to examine whether or not steroid administration allows in vivo induction of foreign gene expression in the oviduct of laying hens. The chloramphenicol acetyltransferase reporter gene driven by several viral and cellular promoters with or without steroid response elements was transfected by in vivo electroporation. The results indicated that in vivo, as observed in vitro, steroid administration induced transcriptional activities of the promoters with steroid response elements but it did not do so without steroid response elements. Our data implicate, therefore, that in vivo induction of foreign gene expression is possible in the oviduct of laying hens, and that the present in vivo gene transfer approach would serve as a useful tool to elucidate the mechanism of tissue-specific and steroid-induced transcription of chicken egg white genes.