The assemblage of myxomycetes (plasmodial slime molds) associated with cloud forests of the Maquipucuna Cloud Forest Reserve in the western Andes was investigated. Within three study sites located along a gradient extending from 1200 to 2700 m above sea level, a clear pattern of decreasing myxomycete diversity and productivity with elevation was apparent. As such, these data conform to the pattern of "reverse diversity" for myxomycetes in the neotropics, with higher diversity for less mesic forest types than for more mesic forest types. Canonical correspondence analysis of myxomycete abundances in relation to microhabitat parameters revealed three major ecological assemblages: wood-, litter- and inflorescence-inhabiting species. All three assemblages include a number of specialized species, with the assemblage associated with litter being the most diverse and the one associated with inflorescences being the most distinctive. In addition, samples from the microhabitat represented by the cover of epiphyllic liverworts on living leaves regularly produce myxomycetes in moist chamber culture but with few sporocarps and no evidence of any specialized species. At least near ground level, bark-inhabiting (corticolous) myxomycetes are uncommon in the cloud forests sampled in the present study.