This study reports on the relationship of glutathione to the recovery and death of red-osier dogwood,CornussericeaL., plants from "near-lethal" (NL) heat stress. Shoots of dormant red-osier dogwood plants were exposed to 51 °C for 1 h during early February, and then incubated in the dark at either 0 or 23 °C post-stress environment (PSE). In a previous study, NL heat stress treated plants incubated at 23 and 0 °C PSE recovered and died, respectively. Reduced and oxidized forms of glutathione (GSH and GSSG, respectively) were measured with HPLC at 365 nm absorbance after 0 h, 24 h, 2 weeks, and 4 weeks PSE, respectively. Incubation of the NL heat stress treatments for 24 h at 23 ± 3 °C prior to post-treatments resulted in a significant decrease of GSSG and slight decrease of GSH. In contrast, the sudden exposure of NL stressed plants to 0 °C for 24 h resulted in a significant reduction of both GSH and GSSG levels after 2 and 4 weeks incubation. At 23 °C PSE, GSH and GSSG levels of NL heat stressed plants increased, while at 0 °C PSE the levels of both decreased.