The horticulturally important Myrtaceae genera which produce edible fruits are Psidium, Eugenia, Syzygium, Feijoa, Campomanesia, Myricaria, etc. Psidium guajava (common guava) is the most important among all the edible Myrtaceae fruits and is now a commercial crop of nearly 100 countries of the world. The other important fruits in these genera are Feijoa and Syzygium which are commercially grown in some countries. Alternatively, Leptospermum and Kunzea produce commercial important honey’s. The International Society for Horticultural Science is organizing the 4th International Symposium on Guava and Other Myrtaceae at Cairns, Australia from 20-25 November 2016. Previous symposia hosted in India, Mexico and Brazil provideda platform for interaction by academia, researchers, extension and industry specialists who will present their latest results and deliberate on a number of challenges facing Guava and other Myrtaceae crops.