The contribution to woody plant diversity by lianas was examined in a lowland and hill dipterocarp forest in Peninsular Malaysia. Species richness of lianas is found to be as high as that visually found in the species-rich moist forests of South America. As in Africa and South America lianas appear to constitute about one-quarter of the woody flora in the evenvet lowland forests of Peninsular Malaysia. Consequently the total woody plant diversity in Peninsular Malaysia is at the same level as that found in the ever wet forests of South America. The present study also confirmed the existence of intercontinental variation in liana floristics with Annonaceae being the dominant liana family in Asia. Another distinct feature differentiating Malaysian forests from the rest of the tropics is the dominance of rattans among the Malaysian liana flora. These plants appear to be particularly abundant in the upper hill dipterocarp forests. While their role in the ecology of the forests deserves a more critical examination the potential for cultivating them in the upper hill dipterocarp forests should also be looked into.