The EFSA Panel on Plant Health performed a pest categorisation of Eulecanium giganteum (Hemiptera: Coccidae), the giant eulecanium scale, for the territory of the European Union, following the commodity risk assessment of Acer palmatum plants from China, in which E. giganteum came to attention as a pest of possible concern. The pest is only known to be present in Asia, where it has been reported from China, India, Iran, Japan and eastern Russia (Primorsky Krai). The pest has not been reported within the EU. It is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. It is polyphagous, feeding on broad-leaf trees and shrubs assigned to 41 genera in 22 plant families. Host plant species commonly found in the EU include apricot (Prunus armeniaca), elm (Ulmus spp.), grapevine (Vitis vinifera), maple (Acer spp.), oak (Quercus spp.), oriental plane (Platanus orientalis), pomegranate (Punica granatum), quince (Cydonia oblonga), silkworm mulberry (Morus alba), walnut (Juglans regia), and several ornamentals. Climatic conditions and availability of host plants in southern EU countries would most probably allow this species to successfully establish and spread. However, EU native natural enemies are anticipated to provide biological control and therefore reduce potential impacts. Phytosanitary measures are available to reduce the likelihood of entry and spread. E. giganteum satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest, other than the criterion on impact which is a key uncertainty.