The specific epithet erythrophaeus originates from the Greek words ερυ𝛉ρος ("red" or "bloody") and Φαιος ("dark"), and refers to the mushroom's characteristic bruising reaction.

Its shape is initially hemispherical, then expanding to be convex or conical, ending up flat, or even slightly concave.

[1][2] The gills are free from the stipe, and often attached to a collar-like structure called a collarium.

They turn reddish-brown when mounted with iodine-based reagent (are dextrinoid) and they stain readily by Congo red.

The cheilocystidia measure 30–93 x 8–14 μm, and are narrowly club-shaped to cylindrical, and sometimes have a forked apex.

Leucoagaricus erythrophaeus differs from L. flammeotincta, by its pseudocollarium, orange staining gills and trichodermal elements on cap.