Assiminea zilchi is a species of minute, salt-tolerant snail with an operculum, an aquatic gastropod molluscs, or micromolluscs, in the family Assimineidae.
The length of this species varies between 2.8 mm and 3.2 mm, its diameter between 1.7 mm and 2.0 mm.
This species occurs in Thailand in brackish waters.