ABSTRACTThe results of this study involving basidiospores ofG. juniperi-virginianaeindicate that freeze-substitution is a valuable technique for TEM studies of fungal spores. Although more spores were damaged in the freeze-substitution protocol than in the chemical fixation protocol, the advantages afforded by the former technique greatly outweighed losses caused by such damage. The quality of fixation provided by freeze-substitution was equal to or better than that provided by chemical fixation for virtually every spore component except lipid droplets. Freeze-substitution also yielded information that was not available from chemically fixed samples. Such information related to Golgi bodies and vesicles, multivesicular bodies, vacuoles and microtubules.