Chemical studies of organic extracts from cultures of the coprophilous fungus Bombardioidea anartia have led to the discovery of bombardolides A--D (1--4), a series of new antifungal and antibacterial metabolites. Three of these metabolites (1--3) were obtained as inseparable pairs of geometric isomers. A new 3-substituted phenol (5) and the known compound asterriquinone B4 were also encountered. The structures of compounds 1--5 were determined by analysis of NMR and MS data.