The Western blue duiker is a small antelope recorded at Central African rainforest sites. It has a dark band across the hips, and 97% of the detections used in one camera-trap activity analysis were made during daylight.
A 2019 review describes the coat as gray-brown overall, grayer on the flanks and darker on the back. A distinct black band crosses the hips to the tail base, contrasting with the very pale brown rump and thighs. The underside is whitish, and the tail is black above and white below.
Camera surveys at 12 sites in four Central African countries in 2014 and 2016–2019 recorded 2,562 independent detections. Of these, 2,474, or about 97%, were during daylight, leading the authors to classify the species as strongly diurnal at the survey sites.
An extinction-risk assessment has not been added yet.