A population of Impatiens glandulifera Royle, an invasive plant species native to the Western Himalayas, was recorded in 2013 near the village Gorno Sedlarce in the north‐western mountainous region of the Republic of Macedonia. I. glandulifera is a new alien species to the Macedonian flora. The surveys revealed an intensive growth and a low to medium density population of I. glandulifera. The population's density was not quantified, but several stands of different sizes were found. A rapid ecological risk assessment, mainly based on knowledge about invasion histories in North–Western and Central European countries, showed that this species, which is on the EPPO List of Invasive Alien Plants, is a serious threat to Macedonian biodiversity. Biological invasions of I. glandulifera affect biodiversity worldwide, and, consequently, the invaded ecosystems may experience significant losses in economic and cultural values. There is a clear need to develop a strategy for control of I. glandulifera to protect biodiversity, as a whole.