PURPOSE. To investigate the effects and possible mechanisms of rat bone marrow mesenchymal stem cell (BMSC) transplantation on the light-damaged retinal structure and the apoptosis of photoreceptors. METHODS. DAPI-labeled BMSCs were transplanted into the subretinal space of light-damaged Sprague-Dawley rats 10 days after exposure. BMSCs were cultivated with the supernatant of homogenized retina (SHR). RESULTS. The outer nuclear layer (ONL) contained significantly more cells and the percentage of apoptotic ONL cells was significantly reduced in the BMSC transplantation group than in the phosphate-buffered solution injection group or the light damage group. Most DAPI-labeled BMSCs expressed brain-derived neurotrophic factor (BDNF). There was elevated basic fibroblast growth factor (bFGF) and BDNF immunoreactivity in the retinas of the BMSC transplantation group compared with the light damage group. In vitro culture showed that 10% of BMSCs changed from fusiform shape to multipolar shape. A fraction of cells expressed MAP2 or glial fibrillary acidic protein, and some cells expressed bFGF or BDNF when cultivated with light-damaged SHR for 7 days. CONCLUSIONS. BMSC subretinal transplantation could inhibit photoreceptor apoptosis and slow down retinal damage in light-damaged eyes. BMSCs could express bFGF (in vitro) and BDNF (in vitro and in vivo), pointing to potential trophic and protective effects on light-damaged retinas.