The phenomenon of hhh Europe has been observed for over 100 years. In this time, many attempts have been made to describe this phenomenon considering biotic, abiotic and anthropogenic factors. Recently, an increasing intensity of bacterial tree diseases has been observed both in Europe and around the world. Moreover, climate change is contributing to an increase in the range of pathogens. The aim of this publication was to highlight the most important bacterial diseases occurring on oaks around the world, and to discuss the potential threat to native oaks occurring in Central Europe: English oak (Quercus robur L.) and sessile oak (Quercus petraea (Matt.) Liebl.). The main focus was on three diseases caused by different bacteria: bacterial leaf streak (caused by Xylella fastidiosa), acute oak decline (caused by Gibbsiella quercinecans, Rahnella victoriana and Brenneria goodwinii) and drippy nut disease (caused by Brenneria quercina—formerly Erwinia quercina). At present, these are the only known bacterial diseases that cause damage to oak stands. Information on each of the above-mentioned diseases is given in the review, ranging from their origin, importance, list of host plants and their potential threat to native oaks of Central Europe.