Over the past few decades technological advances in transcriptomics, proteomics, metabolomics, and glycomics along with the ability to selectively knockout genes of interest has greatly advanced our understanding of maternal-conceptus interactions that are essential for the establishment and maintenance of a successful pregnancy. This knowledge provides a foundation from which to build research endeavors to help resolve infertility, embryonic loss and recurrent abortion in humans, captive wild animals and important farm species. The present volume on “Regulation of Implantation and Establishment of Pregnancy in Mammals” brings together current reviews from leading experts to address the diversity of mechanisms by which species establish and maintain pregnancy. Implantation in rodents, dogs, pigs, cattle, sheep, horses, primates, humans and embryonic diapause in wild species are discussed. Reviews will provide current knowledge on the role of endometrial steroid receptors, adhesion factors, cytokines, interferons, steroids, prostaglandins, growth factors and immune cells involved with regulation of conceptus development.