In three forests that differed in annual rainfall and seasonality the probability of a liana with a stem >=2.0 cm stem diameter reaching the canopy was >50 percent. Lianas reached the canopy at significantly smaller size-classes (1.5 cm) in the wet aseasonal forest suggesting that this estimate changes with forest type. Nevertheless as a general rule we suggest that 2.0 cm is the minium stem diameter to examine the abundance and diversity of canopy lianas or canopy competition between lianas and trees.