Lactarius fumosus has a glabrous, somtines wrinkled brown convex cap with a shallow depression when fully open. It has close off-white subdecurrent gills that become dull cream-yellow. Like Lactarius lignyotus and Lactarius gerardii var. subrubescens, Lactarius fumosus has latex that is white and doesn’t change color, but the flesh and gills stain when cut or bruised. In this case, the color of the satin is a pinkish-salmon. Stipe is smooth and concolorous with cap, but paler at the base. Edibility is unknown.