This is the first study to measure the diversity of woody taxa in Giza Zoo garden considered an extraordinarily diverse hotspot with an unusually high number of woody taxa found nowhere else in Egypt especially, tropical species. This study was conducted in several stages, preparation, inventory, analysis, and evaluation. The study uses quantitative methods to evaluate the woody taxa diversity and the threatened species which are conserved in the garden across their main sections. Therefore, species richness, Shannon and Simpson's diversity indices were estimated. Also, the species importance value index, a measure of how dominant a species is in a given population, and conservation status were used to evaluate the conservation potential of the trees in the garden. The garden plays a vital role in conserving 145 individuals as threatened trees belonging to 18 species that are either endangered, near threatened or vulnerable according to the IUCN red list. The Weak conservation procedures in the zoo garden have led more individuals of species that are over-mature and over-aged to their demise therefore, it is feared that may be lost from the garden. So, it's imperative to immediately restore these lost species in the garden and place their diversity on a pathway to recovery. We warn to increase the area of impermeable pathways and more buildings that will increase the stresses upon the garden trees. Therefore, we suggest technical support for the botanic garden as the experts of the Timber Trees department will be essential for allowing this valuable garden to continue its work and expand its collections of critical but under-represented species. Also, the inventory of tree species entity and structure in this study will assist as a guide tool for the administration of the garden to reach the Egyptian sustainable development goals by 2030 and the global goals by 2050.