AEstract. This review evaluates the quality of bovine embryos developed from in vitro matured (IVM) and fertilized (IVf) oocytes cultured in either serum free or serum containing media. Bovine embryos cultured in serum supplemented medium contain numerous cytoplasmic lipid droplets and immature mitochondoria compared to those cultured in serum free medium. The accumulation of cytoplasmic lipids in embryos developed in serum containing medium may be a result of incorporation of lipoproteins from the serum and may result in impaired function of mitochondria. The improved serum free media (IVMD101 and IVD101) offer several advantages over culture in serum containing medium, including increased rates of blastocyst formation and higher cell numbers. Additionally, the survival and hatching rates of embryos produced in serum free media after post thaw culture were superior to those of embryos produced in the serum containing medium, suggesting that the abnormal accumulation of cytoplasmic lipids in embryos may have a negative effect on the sensitivity of embryos to chilling and freezing. These serum free culture systems have proven to be beneficial for the production of good quality embryos from IVM IVf bovine oocytes. furthermore, recent studies have shown a correlation between mitochondrial function (oxygen consumption) and embryo quality. A new method using scanning electrochemical microscopy may be capable of asessing the viability and developmental potential of bovine embryos.