A study was carried out to establish the relationship between Parkia speciosa (local name Ṭah-lim) and nectar-feeding bat, Cynopterus sphinx with respect to pollination, and effects on fruit production. Eight flowering trees of P. speciosa from Lengteng Wildlife Sanctuary were selected for experimentation. During the flowering season of stink bean from August to November, 2013 visual observations were made twice a week during the night at 18:00 to 05:00 h. C. sphinx visits the capitulum and collects the nectar by landing on the capitulum. Duration of nectar collection by bat is around one second, and then visited the next flower to collect nectar simultaneously. To ascertain the pollination by bats, we captured the bats using mist nets. The yellow cream colour pollen was attached on their facial, neck region, abdomen and wings. This reveals that this bat provides a vital reciprocal service to P. speciosa flowers in terms of pollination. The present study also revealed that seasonality and availability of flowers influenced the frequency of bats. Also compared the average number of fruit production between frequently and randomly visit of P. speciosa trees by bats and observed that frequently visited trees by bats produced more fruits than randomly visited trees (P > 0.05).