The vapor pressure (p(sat)) of methyl oleate was measured with and without the addition of 0.2 mass % of the antioxidant, stabilizer tert-butylhydroquinone (TBHQ). The measurements were made by the gas saturation method with a temperature range of 303.15-343.15 K. In the absence of TBHQ, oxidative decomposition severely compromised the measurements, as evidenced by dramatic decreases in the measured psat for repeat measurements at 323.15 K. When combined with a room-temperature N-2 flush of the apparatus, the addition of 0.2 mass % TBHQ limited the decomposition to insignificant levels and resulted in repeatable measurements of P-sat. Simultaneous measurements on the control sample n-eicosane (C20H42) yielded values of p(sat) that were in excellent agreement with reference correlations.