The Ian Donald International School of Ultrasound bears testament to globalization in its most successful and worthwhile form. The school was founded in Dubrovnik in 1981. In the Preface of the First Edition in 2004, we were proud to announce that the school had grown to 8 branches. Since then, the growth has been meteoric and now consists of 129 branches in almost every corner of the globe. The reason for this success has been the tireless and selfless efforts of the world’s leading authorities in ultrasound who are willing to dedicate their valuable time without reimbursement to teach sonologists and sonographers throughout the world. Our teachers put national, religious, political, and other parochial considerations aside as they strive to improve the care of all women and fetal patients. Politicians in the countries represented by our school have much to learn from the purity of spirit that exists throughout our international family. We believe that Ian Donald is smiling down from heaven at the school that bears his name. In the educational efforts of the 129 branches of the Ian Donald School, there is clearly a need for a textbook to complement and supplement lectures and didactic sessions. The first, second, third, and fourth textbooks were successful in this endeavor, but with the explosion of knowledge, it was clear that an expanded and updated fifth edition would be invaluable. The current edition illustrates the latest developments Silhouette ultrasound and four-dimensional ultrasound which have been pioneered by our school. For the sake of simplicity, our book is divided into three sections. Section 1 deals with a variety of topics that lay the foundation for the rest of the book. Section 2 addresses the myriad subtopics in obstetric ultrasound that optimize the care of pregnant women and fetal patients. The last section addresses the essential role that ultrasound plays in many dimensions of clinical gynecology.