Root climbers constitute a distinctive group within climbing plants and some evidence suggests that they are associated with high precipitation and low light availability at local scales, which is in contrast with general patterns of liana distribution in the tropics. The influence of precipitation and seasonality on the occurrence of root climbers was evaluated both globally and in the tropics. The presence/absence of root climbers was recorded in 174 sites of Alwyn H. Gentry Forest Transect Data Set. The effects of mean annual precipitation and dry-season length (and temperature) on their occurrence were analysed using logistic regressions. Root climbers were significantly more frequent in sites with greater precipitation and reduced seasonality. Increasing temperature reduced root-climber occurrence in tropical sites, but this effect was marginally significant at a global scale. Dry and open habitats appear unsuitable for root climbers. This can be explained by the susceptibility to desiccation of adventitious roots and/or the low acclimation ability of these climbers to high irradiance.