Egeria densa Planch. is reported for the first time for the aquatic flora of Egypt. This species is a South American aquatic plant species considered highly invasive outside of its original range. In Egypt, the species may have been introduced as an aquarium plant and has long been wrongly identified as Elodea canadensis. However, it was collected from wild habitat at the northern lake of Egypt (Idku Lake). The article presents data on the comprehensive morphological and palynological features, distribution, ecological notes and conservation status in Egypt of the newly recorded taxon, as well as photographs of herbarium samples, were also provided. This species has not been reported yet in North Africa, except for Algeria. The new record of its presence in Egypt fills the gap in its general distribution in the warm temperate region of the world. Based on the present study Hydrocharitaceae in Egypt, are now represented by 7 genera viz. Halophila, Thalassia, Ottelia, Vallisneria, Elodea, Najas and Egeria. The present data indicate that there are insufficient collections of Egeria densa in Egypt considering that the aquatic flora of Egypt is poorly known.