Mitochondria play an essential role in generating energy for embryo development and maintaining embryo metabolism through key cellular functions including ion homeostasis, amino acid metabolism, glycolysis, fatty acid metabolism, signal transduction and apoptotic regulation. Recent literature suggests that mitochondrial content and function may be related to implantation success and embryo viability. Some studies have linked increased levels of mitochondrial DNA to aneuploidy, advanced maternal age and euploid blastocyst with implantation failure, while others have failed to demonstrate similar findings. This review aims to provide an overview of the current literature surrounding the possibilities of using mitochondria as an additional biomarker for infertility treatment outcome and summarize the reasons as to why there are inconsistencies in these studies.