Given the current extinction trends, conservation practitioners and policy makers are confronted with making fast decisions based on the available data. However, there is an alarmingly lack of data on which management actions can be based, even for the most widely known group, the tetrapods. The need for data is so central that one of the main targets of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services is to “facilitate access to knowledge and data needed.” In fact, institutions such as zoos have been collecting data on various species for many years, which might be useful for conservation purposes. Together, the 837 member institutions of Species 360 (formerly International Species Information System) hold approximately 4000 species, including 15% of the world’s threatened tetrapods. We found that with the current number of species, zoos are able to fill knowledge gaps in the pool of available data by more than 40% in five of nine demographic variables analysed. However, these data are not being used. While scientists are not presently considering the origin of the data they are using (more than 80% of the data from primary databases with demographic information on tetrapods do not report their origin, i.e. captive or wild), they are still unreceptive to using known captive data. We did find that there is a percentage of information loss, ranging from 10 to 54%, when extrapolating data from either captive or unknown origins to parameterize models in the wild. Nevertheless, we must be aware of these uncertainties and start taking them in consideration in further analyses. The information that the zoo network can provide is highly valuable, particularly when there is no time to gather more data and conservation actions are crucial to slow down the current rates of extinction.