Adenovirus-mediated gene transfer to retinal cells was evaluated using the replication-defective recombinant adenovirus vector Ad2/CMVlacZ-l (coding for beta-galactosidase) both in an in vitro murine culture model and in vivo in adult mice. In vitro, no difference in infectability of neuronal and glial cells was observed, and 50% of neurons expressed the exogenous gene at low viral concentration (10 pfu/cell). In vivo, intraocular injection of 3 x 10(6) pfu AdZ/CMVlacZ-l resulted in expression of the transferred B-galactosidase gene in retinal pigment epithelium and ganglion cells. These results demonstrate that Ad2/CMVlacZ-l is an effective vector for gene transfer into retinal cells.