The host susceptibility of Malaysian Paragonimus westermani was observed in cats, dogs and rats, infected with metacercariae. In rats, worms were harboured in the muscles and the flukes were morphologically similar to the excysted metacercariae except for their slightly larger body size. In cats, about a half number of the flukes were recovered from muscles and 40% from cysts found in the lungs. Majority of the flukes from these cysts were mature. In dogs, few mature flukes were obtained from cysts in the lungs and about 90% of flukes were recovered from muscles. The flukes from the muscles of cats and dogs were of the same juvenile stage as those from rats. The juvenile flukes recovered from muscles of the animals were orally given to dogs and cats. Majority of the flukes were found in cysts in the lungs and most of them were fully mature. However, some juvenile flukes still remained in the muscles of cats and dogs. Therefore, the Malaysian P. westermani has a higher final host susceptibility than those from other localities. The present study suggests that many species of animals living in Malaysian jungle serve as paratenic hosts and may play an important role in the completion of the life cycle of P. westermani in Malaysia.