This paper summarizes the present state of knowledge of the vascular plants endemic to the Krkonoše Mts. The species given in previous lists but excluded from the present one are also discussed together with the history of opinion of their status. Some endemics are of Holocene age, e.g. Sorbus sudetica is the result of a past hybridization while others originated from continuous differentiation of small populations over time. Some endemic species of other genera, for example, Hieracium, Taraxacum and Alchemilla appear to be older in origin, representing relict populations which occurred at low altitudes at least during the last glacial period. Their age is unknown, because it is unknown, when and how they evolved.