**Abstract**

Eucalyptus is the common name of a set of exotic species present in the Brazilian territory. They have a strong invasive potential which is detrimental to the preservation of native floral formations, particularly in protected areas. This research seeks to (i) understand the stage of eucalyptus invasion in the Brasilia National Park; (ii) identify the main vectors of the invasive populations and (iii) verify the possible role of the adjoining Brasília National Forest in the invasion and (iv) consider possible conflicts between the roles of these two different categories of protected areas. A set of phytosociological sample areas were defined inside the park to pinpoint different eucalyptus populations. Findings indicate that eucalyptus populations inside the park behave invasively, having advanced 186.30 meters from their point of origin over the span of 45 years. Among the possible contamination vectors are a neighbouring nursery run by the local government and eucalyptus plantations in the adjoining Brasília National Forest. Results indicate the need for management actions to avoid continual seed dispersal by examined populations. They also indicate that the distinct conservation goals of national forests and national parks must be considered, especially when they are neighbours.

**Keywords:** Biological invasions, Brasília National Park, Cerrado, vectors of contamination, Brasilia National Forest
