A main avenue of defense against fungal infection uses oxidative killing of these and other microorganisms. Consequently, the ability of fungi to withstand an oxidative challenge has important implications for their ultimate pathogenicity in a host organism. Fungi also serve as an excellent model system for handling of reactive oxygen species in eukaryotic cells. For these reasons, a great deal of work has been invested in analyzing pathways involved in and the mechanisms regulating oxidative stress tolerance in fungi. The goal of this review is to discuss the current state of knowledge underlying the ability of fungal cells to mount a response to oxidative stress via activation of transcription factors. Studies in Saccharomyces cerevisiae have identified multiple transcriptional regulatory proteins that mediate tolerance to oxidative stress. Experiments focused on the fission yeast Schizosaccharomyces pombe have led to the discovery of protein kinase cascades highly related to mammalian stress-activated protein kinases. Recent studies on the pathogenic yeast Candida albicans have allowed analysis of the role of a critical oxidant-regulated transcription factor in this important human pathogen. Further understanding of oxidative stress resistance pathways in fungi is an important step toward understanding the molecular pathogenesis of these microorganisms.