This paper presents the distribution of Pedicularis sylvatica, an endangered species across the whole Poland. In order to illustrate its dynamics four time periods were taken into consideration: before 1900, 1901-1950, 1951-1990 and after 1990. Until the present, 599 localities of P. sylvatica, have been known, half of which, i.e. 276 were recorded during intensive studies on wetland habitats in the years 1951-1990. Numerous localities – 195, were also recorded after 1990. In the 19th century 93 sites were documented and 91 in the first half of the 20th century. The analysis of the dynamics of P. sylvatica, shows that despite discovering new localities, primarily in the south of the country, the species exhibits recessive trends, on some areas, especially in the north.