This study examined how seed feeding by the Ryukyu long-furred rat Diplothrix legata affects germination of five plants (Cerasus campanulata, Actinidia rufa, Ficus erecta, Oreocnide pedunculata, and Melastoma candidum) in Okinawajima Island, Japan. The germination rates of seeds from fresh fruit and fecal pellets of two captive rats, as well as the feeding behaviors, were observed. Most of C. campanulata seeds, which were the largest among the five plant species, were crushed by rats. Seeds of the other four plants were swallowed whole; however, the excretion rates were low (< 20%). The germination rates of A. rufa, F. erecta, and M. candidum from fecal pellets were significantly lower than that of seeds from fresh fruits. The rats showed a higher excretion rate for the seeds of O. pedunculata, and the excreted seeds showed a similar germination rate to that of seeds from fresh fruits, which might be attributed to the small-sized seeds with hard coats. Some fruits of A. rufa and F. erecta were dropped before they were completely consumed. Thus, undigested seeds and dropped seeds might be dispersed by D. legata, although this species should be regarded mainly as a seed predator.