Species in this genus, formerly classified as a subgenus in Collybia, have fairly large caps (typically larger than 5 centimetres (2.0 in) broad), and have a pinkish-tinted spore print.

Microscopically, they are characterized by having spores and basidia that are dextrinoid—staining deep reddish to reddish-brown with Melzer's reagent when tested for amyloidity.

The gills are whitish to pinkish cream in color, and have an adnexed attachment to the stem.

[6] Spores in this species are typically spherical to ellipsoid in shape, and translucent (hyaline).

Rhodocollybia is characterized by having an endosporium (inner wall of the spore) that is dextrinoid (staining yellowish or reddish-brown in iodine-containing solutions such as Melzer's reagent), and sometimes cyanophilous.