trans-3-Hexene ignition delay times were measured behind reflected shock waves for fuel-lean (Phi = 0.5), stoichiometric (Phi = 1.0), and fuel-rich (Phi = 1.5) mixtures between 1080 and 1640 K, at pressures between 1.2 and 10 atm. Two fuel concentrations (1000 and 5000 ppm trans-3-hexene) diluted in argon were examined, and the ignition delay times were obtained by following OH* radical chemiluminescence emission. The experimental results satisfied the Arrhenius equation, and the influences of pressure, equivalence ratio, fuel concentration, and dilution gas on trans-3-hexene ignition behavior were discussed. The Lawrence Livermore National Laboratory (LLNL) model overestimates the low-temperature reactivity and underestimates the pressure-dependence at high-temperature. Improvements have been made to the LLNL model, and the modified mechanism offers better predictions for the ignition delay times of this work as well as the shock tube, rapid compression machine, and jet stirred reactor experimental data from the literature. Reaction pathway and sensitivity analysis were performed to gain insight into the trans-3-hexene oxidation chemistry.