We are pleased to present our readers the proceedings of the International symposium on "New Aspects of Human Polymorpho- nuclear Leukocytes" which was held in Freiburg im Breisgau, FRG, from October 26-28th, 1989. The meeting provided an unique framework for close interaction between scientists from various disciplines, including bioche- mistry, biology, physiology, pathology, clinical chemistry, hematology, gynecology, surgery, intensive care medicine, nephrology, rheumatology, and infectious diseases. We would like to express our gratitude and appreciation for all those who have stimulated, encouraged, and supported us to hold the symposium in Freiburg. This endeavor could not have been possible without the generous financial support of Asid- Bonz (Boblingen), Bayer AG (Leverkusen), Bayropharm GmbH (Koln), Baxter (Munchen), Ciba-Geigy (Wehr/Baden), Cilag GmbH (Sulzbach), Fresenius AG (Oberursel), Gambro (Martinsried), Gry-Pharma GmbH (Kirchzarten), Hoechst AG (Frankfurt), Hospal (Nurnberg), Knoll AG (Ludwigshafen), Lederle-Cyanamid (Wolfratshausen) , E. Merck (Darmstadt), MSD Sharp and Dohme GmbH (Munchen), Pfizer GmbH (Karlsruhe), and Kabi/Pfrimmer (Erlangen).We are indebted to Mrs. I. Szkibik for her invaluable ass i- stance both with the organization of the meeting and the pre- paration of the manuscripts.