Recent reports indicate that trees can survive to be 1000 years old in the Amazonian rain forest. This appears to contradict the idea that tropical rain forests are highly dynamic systems. However, there is very little information on how common these ancient trees are. Tropical rain forest turn-over rates have been estimated to be less than 400 years, which would suggest that millenary trees would be non existent or very rare. Recent radiocarbon-based dating techniques suggest that centuries-old trees are common among big canopy trees, but it is not clear how accurate the technique is compared with other methods: age determinations on this long timescale are necessarily based on estimates, and some methods may be more reliable than others. To examine the apparent contradiction between tree age and forest dynamics tree-ageing methods should be discussed in the context of the ecological significance of longevity in tropical forests. These issues are important for understanding the structure, dynamics and conservation of this highly diverse ecosystem.