Implantation of silastic membranes between neural tube and somites at somitic levels 20‐24 in 30‐somite‐stage chick embryos results in separation of early migrated neural crest cells of the dorsal root ganglion (DRG) anlage from the neural tube and their death within a few hours [Kalcheim and Le Douarin, (1986) Dev. Biol., 116, 451‐460]. The in vivo effects of brain‐derived neutrotrophic factor (BNDF) on survival of HNK‐1 immunoreactive DRG cells separated from the tube were examined by implantation of laminin‐treated silastic membranes (controls) or BDNF/laminin‐treated membranes. In the presence of BDNF/laminin‐treated membranes, 20/25 grafted embryos fixed 10 h after implantation, contained many rescued cells on the operated side. In contrast, only a few rescued cells on the operated side. In contrast, only a few rescued cells were observed in sections on the operated in 2/11 embryos implanted with laminin‐treated silastic membranes, and no rescued cells at all could be detected in embryos implanted with NGF/laminin‐treated (seven embryos) or untreated silastic membranes (12 embryos). The data presented support the hypothesis that early survival and differentiation of neural crest‐derived sensory cells depend on central nervous system‐derived factor(s). Moreover, this is the first evidence for the in vivo activity of BDNF on survival of developing DRG cells.