Three monocentric and two polycentric obligately anaerobic zoosporic fungi were isolated from the rumen, freshly voided feces, and dry and moist feces. Rumen isolates were morphologically similar to fecal isolates from the same animal. The monocentric isolates werePiromyces communis,Neocallimastix frontalis, andCaecomyces communis. The polycentric isolates wereOrpinomyces bovisandOrpinomycessp. type PC3.Piromyces communisandN.frontaliswere obtained from feces stored for 3 and 6 months, respectively.Orpinomyces bovisandOrpinomycessp. type PC3 were isolated from dry feces, but not moist feces, stored for 3 and 6 months, respectively.Caecomyces communiswas isolated only from feces stored for 6 weeks. All the isolates, exceptC.communis, formed melanized sporangia in pure culture. Structures that were morphologically similar to the melanized sporangia of rumen fungi were observed in fecal smears.The fecal isolates grew under conditions similar to the rumen, but not under aerobic conditions.Key words: rumen fungi, Chytridiomycetes, fecal fungi.