The taxonomy, distribution and ecology of eight short-stalked species of Chaenothecopsis are described. The species are parasitic, parasymbiotic on lichens or free-living algae or saprophytic and are often quite specific with respect to host. A key to the species is supplied. Two new species, C. kalbii Tibell & K. Ryman, occurring in Australia and the tropical Americas, and C. pilosa Tibell & K. Kalb, known from tropical South America and Africa are described. The following new combinations are suggested: C. hospitans (Th. Fr.) Tibell, C. ochroleuca (Koerber) Tibell & K. Ryman and C. subparoica (Nyl.) Tibell. A lectotype is selected for C. hospitans and a neotype is designated for C. ochroleuca, Chaenothe copsis brevipes is reported new to Europe