The Complementarity of Women and Men provides a Catholic Christian case that men and women are in certain respects quite different but also have a positive, synergistic complementary relationship. Although differences and their mutually supporting relationships are focused on throughout the volume, men and women are assumed to have equal dignity and value. This underlying interpretation comes from the familiar, basic theological position in Genesis that both sexes were made in the image of God. After a cogent philosophical introduction to complementary differences by J. Budziszewski, this position is developed from theological, philosophical, and historical perspectives by Sr. Prudence Allen. Next Deborah Savage, building upon the writings of St. John Paul II, gives a strong theological basis for complementarity. This is followed by Elizabeth Lev’s chapter presenting new and surprising art history evidence from the paintings of Michelangelo in the Sistine Chapel supporting the complementarity interpretation. A final chapter by Paul Vitz documents and summarizes the scientific evidence supporting sexual difference and complementarity in the disciplines of psychology and neuroscience. As a consequence of both the individual chapters and the integrated understanding they present The Complementarity of Women and Men is a significant contribution to the important, complex, contemporary debate about men, women, sex, and gender.