In experimental stroke, cell therapy can partly reverse some behavioural deficits. Most studies revealed only little if any evidence for neuronal replacement and the observed behavioural improvements appeared to be related rather to a graft-derived induction of a positive response in the remaining host tissue than to cell replacement by the graft itself. The present study was performed to test a murine embryonic stem cell-based approach in rats subjected to endothelin-induced middle cerebral artery occlusion. Efficacy of cell therapy regarding graft survival, neuronal yield and diversity, and electrophysiological features of the grafted cells were tested after transplanting embryonic stem cell-derived neural precursors into the infarct core of adult rats. Here, we show that grafted cells can survive, albeit not entirely, within the infarct core for up to 12 weeks after transplantation and that they differentiate with high yield into immuno- histochemically mature glial cells and neurons of diverse neurotransmitter-subtypes. The transplanted cells demonstrate characteristics of electrophysiologically functional neurons with voltage gated sodium currents that enable these cells to fire action potentials. Thus, our observations show that embryonic stem cell- based regenerative approaches may be successful in an acutely necrotic cellular environment.