Abstract: Objective To investigate the mechanism by which propofol exposure causes PC12 cell apoptosis under hypoxic conditions. Methods PC12 cells were exposed to room air, 35% oxygen, or 5% oxygen (hypoxia) for 24 h in the presence of either 10 μmol/L lipid emulsion or 10 μmol/L propofol. After the treatments, the cell apoptosis was measured by flow ceytometry, and the level of reactive oxygen species (ROS) and the activity of superoxide dismutase (SOD) were evaluated. Results In room air, PC12 cells treated with propofol showed increased apoptosis rate and ROS production as compared with the cells treated with the lipid emulsion; propofol treatment of the cells exposed to 35% oxygen showed obvious enhancement of the apoptosis rate, ROS production and SOD activity. Under the hypoxic condition, propofol treatment even further increased the apoptosis rate, ROS production and SOD activity. Lipid emulsion caused no such changes in cells exposed to room air, 35% oxygen or 5% oxygen. Conclusion Under hypoxic conditions, propofol can cause apoptosis in PC12 cells by inducing oxidative stress injury.