One of the commonly used measures of biodiversity is species richness which is the numbers of different species presented in an area. Typically areas with higher species richness are accorded greater conservation value. However species richness often underestimates true diversity as it does not take into account how different the species are from each other. For example an area with four species of lizards and another area with four species of reptiles (a lizard, a snake, a crocodile and a tortoise) will both be assigned the same value for reptile richness. Nevertheless the second area has greater diversity as it harbours very different composition of reptiles. To correct for this discrepancy, diversity can be measured at higher levels (genus or family or order), but here again a true picture does not emerge due to taxonomic uncertainty and discordance between taxonomic rank and age of the taxonomic group when compared across multiple groups. In this regard, molecular phylogenies are very useful. In this workshop I will introduce the concept of phylogenetic diversity (PD) to illustrate some of these issues and discuss how PD could be used to rate areas and species for conservation action. The workshop will have both theory and computer lab component. In the theory part I will discuss various tree building methods and contrast species richness with PD. In the lab component we will work with an example dataset to calculate PD.