Cardiospermum grandiflorum presents a moderate phytosanitary risk for the endangered area within the EPPO region with moderate uncertainty. 

The risk of further spread within and among countries is moderate. The overall likelihood of C. grandiflorum continuing to enter the EPPO region is moderate because the species is traded by a small number of suppliers. Given the species' known occurrences within the EPPO region and its desirable characteristics as an ornamental, it remains likely that it could be moved non-commercially (e.g., through seed exchange by collectors), resulting in further human-assisted spread. 

Natural dispersal from existing populations within the region is the most likely mode of further spread. The seed-carrying balloons of C. grandiflorum can float for extensive periods in watercourses (e.g., along rivers and across the sea) and are carried by wind and thus can cover substantial distances over short time scales. Under climate change the range of suitable habitat for establishment is expected to expand and shift northwards.