Objective: To assess the effect of propofol on fertilization and early embryo development in a mouse IVF model.Design: Controlled study.Setting: Mouse IVF.Intervention(s): Mouse oocytes were exposed in vitro to propofol at a concentration of 0 (control), 50, 250, 500, 1,000, or 5,000 ng/mL for 30 minutes, washed, and inseminated. Thereafter, fertilization was assessed. Subsequent in vitro development to the blastocyst stage was monitored daily. The potential to activate parthenogenetically oocytes also was evaluated by looking for spontaneous extrusion of the second polar body or development to the two-cell stage. In a second step, a pure propofol solution was added to culture medium and used as a standard.Main Outcome Measure(s): Two-cell and blastocyst-stage embryo.Result(s): Where fertilization occurred, subsequent embryo cleavage and development up to the blastocyst stage was affected significantly by the presence of propofol solution in the medium, (i.e., 3% to 41%) in comparison with the control group (76%). Exposure of unfertilized oocytes for 30 minutes to propofol results in a parthenogenetic activation of 33% to 60%, which was significantly higher than the control (10%). When oocytes were kept in propofol for 24 hours, a mean of 30% of activation was observed as compared with 0.5% for the control.Conclusion(s): We can conclude from these experiments that even a brief exposure of cumulus-enclosed oocytes to a low concentration of propofol is deleterious to subsequent cleavage. Exposure of unfertilized oocytes to propofol results in a high degree of parthenogenetic activation.