While the academic literature widely asserts that production diseases have a significant financial impact on poultry production, these claims are rarely supported by empirical evidence. There is a risk, therefore, that the information needs of poultry producers regarding the costs associated with particular diseases are not being adequately met. A systematic literature review of poultry production diseases was undertaken, first, to scope the availability of studies that estimate the financial impacts of production diseases on poultry systems and, second, on the basis of these studies, estimates were generated of the magnitude of these impacts. Nine production diseases, selected by a panel of stakeholders as being economically important in the EU, were examined. The review found that the poultry disease literature has primarily an epidemiological focus, with very few publications providing estimates of the financial impacts of diseases. However, some publications have quantified the physical impacts of production diseases and control interventions, for example, using measures such as output volumes, mortality rates and bacterial counts. Using these data in standard financial models, partial financial analyses were possible for some poultry production diseases. Coccidiosis and clostridiosis were found to be the most common production diseases in broiler flocks, with salpingoperitonitis being the most common in layers. While the financial impact of untreated diseases varied, most uncontrolled diseases were estimated to make flocks loss-making. However, in all cases, interventions were available that signficantly reduced these losses. The review reinforces the concern that the available academic literature is not providing sufficient information for poultry producers to decide on financially optimal disease-prevention and treatment measures.