Emerging infectious disease events are dominated by zoonoses: infections that are naturally transmissible from animals to humans or vice versa. A worldwide survey of ~5,000 bat specimens identified 66 novel paramyxovirus species – more than double the existing total within this family of viruses. Also, novel paramyxoviruses are continuously being discovered in other species, such as rodents, shrews, wild and captivated reptiles and farmed fish, as well as in domestic cats and horses. Paramyxoviruses exhibit one of the highest rates of cross-species transmission among RNA viruses, and paramyxoviral infection in humans can cause a wide variety of often deadly diseases. Thus, it is important to understand the determinants of cross-species transmission and the risk that such events pose to human health. Whilst pathogen diversity and human encroachment play important roles, This paper focuses on receptor tropism and envelope determinants for zoonosis of emerging paramyxoviruses.