The 4 Intercontinental Meeting of Hair Research Societies organized by the 5 Hair Research Societies (NAHRS, SHSR, EHRS, AHWRS, KHRS) was held in Berlin, Germany from June 17 to 19, 2004. 514 participants from 40 different countries, worldwide, were able to experience the global unity of researchers and clinicians as well as representatives of cosmetic and pharmaceutical companies during this highly stimulating meeting, the largest gathering of hair research societies ever held. The high-level scientific program combined both a profound insight into current clinical diagnostic and therapeutic aspects, as well as the latest research findings. During the three days meeting, clinical courses, key note and plenary lectures, workshops and satellite symposium with up to 100 oral presentations and 160 poster presentations provided for the latest knowledge in the physiology, pathogenesis and therapy of hair and hair disorders (www.hair2004.com). This special issue of the Journal of Investigative Dermatology Proceedings serves as a record of the progress achieved up to now in the World of Hair.