The developmental pattern of Polystoma indicum Diengdoh & Tandon, 1991 occurring in the urinary bladder of the frogs Rhacophorus nigropalmatus, R. reinwardtii and Polypedates leucomystax from Meghalaya (north-east India) was studied. Non-ciliated larval stages were recovered in the gyrodactyloid-I and post-gyrodactyloid-I stage mostly from the branchial chambers of the tadpoles; only rarely were they found in the intestines. These stages possessed features of bladder-destined forms and showed a gradual acquisition of 2, 4 and then 6 opisthaptoral suckers, coupled with an increase in the size of the body and various structures. While a conspicuous increase was noticeable in the dimensions of the hamuli, the size of the microhooks remained almost the same from the 2-suckered larval stage to the adult. The larval migration to the final destination seems to follow an external route leading to the cloaca of the metamorphosing host. The prevalence data of both the larvae and the adult flukes indicate a preference towards R. nigropalmatus amongst the three rhacophorid host species. The gyrodactyloid-II, i.e. neotenic larvae were not encountered at all either on the external gills of the very young tadpoles or even in the branchial chambers of the older ones.