This small shrew is recorded from Huong Son, Ha Tinh Province, north-central Vietnam. Its back is pale brown, the underside grayish buff, and the tail darker above than below.
The dorsal fur is light brown with pale gray bases, while the underside is grayish buff with gray-brown hair bases. The tail is dark brown above and pale brown below, with longer hairs on its proximal half.
In Crocidura annamitensis, the rear section of the last lower molar is reduced to a cusp and a slight ridge. The first lower incisor has two low cusps. These small features help characterize the animal.
The adult selected as the name-bearing specimen was collected in Vietnam on 12 May 1998. Its skull was removed from the preserved body and cleaned using dermestid beetles. The 2009 description also examined two additional specimens from the same area.
Researchers compared skulls and teeth with similar shrews. The rear section of the last lower molar was more reduced than in Crocidura guy. Alongside coat colour and body size, dental differences helped distinguish the new species.
An extinction-risk assessment has not been added yet.
A 2024 analysis of Vietnamese mammals identified this range-restricted shrew among species with limited protected-area coverage. The study overlaid estimated distributions, suitable habitats and protected areas. Further surveys to establish where the shrew lives would help guide habitat protection.