Dieter's Myotis is known from a specimen collected in the Republic of the Congo. The 2005 paper's abstract describes only one specimen.
It has a very slightly concave forehead and relatively long feet. The wing membranes attach at the bases of the lower legs, and the margin of the tail membrane lacks backward-curving hairs.
The described specimen was collected in a limestone cave at Loudima, Republic of the Congo, in degraded rainforest near a river. The abstract gives no other natural-history records.
An extinction-risk assessment has not been added yet.