Pestalotheols A-D ( 1- 4 ), four new metabolites, have been isolated from cultures of an isolate of the plant endophytic fungus Pestalotiopsis theae. The structures of these compounds were determined by NMR spectroscopy, and 1 is further confirmed by X-ray crystallography. The absolute configurations of compounds 1 and 3 were assigned by application of the modified Mosher method. Pestalotheol C ( 3) displayed an inhibitory effect on HIV-1 LAI replication in C8166 cells with an EC 50 value of 16.1 microM.