The objectives were to determine if tumor necrosis factor (TNF)-α, leukotriene (LT)B4 and 8-isoprostane (IP) were present in the exhaled breath condensate (EBC) and total lung lavage (TLL) of mechanically ventilated rats, 4 and 24 h after administration of Staphylococcal entertoxin (SEB) and to find out if these mediators in the EBC correlate with the concentration in the TLL. Rats were assigned to control (n = 8); 4 h (n = 8) or 24 h (n = 8) groups after SEB. The rats were mechanically ventilated and EBC and TLL were collected for TNF-α, LTB4 and 8-IP. TNF-α was higher in the EBC of rats at 24 h after SEB when compared to control [34.5 (16-62 versus 2 (14-30) pg ml -1, p < 0.05] and also in the TLL [113.5 (70-460) versus 59 (35-79) pg ml-1, p < 0.04]. LTB4 was higher in the EBC of 24 h SEB rats, when compared to control [42 (28-50) versus 36 (29-37) pg ml -1, p < 0.01] and also in the TLL [179 (116-232) versus 114 (80-187) pg ml-1, p < 0.05). 8-IP was similar among the groups. No correlation was observed between TNF-α, LTB4 or 8-IP in the EBC compared to the TLL. TNF-α and LTB4 may be indicators of inflammation and oxidative lung injury but the EBC does not correlate with TLL concentrations.