The role of endocannabinoids in mammalian reproduction is an emerging concept. Cannabinoids have been always identified as being harmful drugs, because of their negative effects on female reproduction. The discovery of endocannabinoids, endogenous lipids that bind to cannabinoid receptors, and of their involvement in procreation permitted better understanding of the significance of cannabinoid/endocannabinoid signalling in fertilization, preimplantation embryo development, implantation and postimplantation embryonic growth. These studies have also opened new perspectives in clinical applications, pointing to endocannabinoid signalling as a new target for correcting infertility, and for improving reproductive health in humans. This review will present endocannabinoids, their target receptors and metabolic enzymes, and will discuss the involvement of these bioactive lipids in female mammalian reproduction.