Over the past 30 years, lianas (woody vines) have become more dominant in Neotropical rainforests. The objective of this study was to compare root functional traits of Neotropical liana and tree communities to delineate traits associated with increasing liana abundance. Fine roots (<2mm diameter) were sampled from 6 liana and 6 tree species (paired by family) on Barro Colorao Island (BCI), Panama with n=10 individuals per species, and chemical, morphological, and symbiont root functional traits were quantified. Liana roots had a higher specific root length (SRL) (cm/g), lower C/N, C/P, and N/P ratios, lower tissue density (g/cm3), and higher branching (forks/cm) than those of trees. Mycorrhizal colonization was significantly different between trees and lianas after excluding the family Fabaceae. Our results suggest that lianas may use a suite of specialized root functional traits to gain an ecological advantage over co-occurring trees, providing insight into the current increase in liana abundance.