My professional interest in antimicrobial agents and contamination control goes back 50 years to my tour as a microbiologist in a field hospital in Europe during World War II. With no experience and relying solely on a military handbook, I prepared thermometer trays with jars of blue bichloride of mercury and pink isopropyl alcohol. A preliminary typhoid diagnosis of one of our cooks resulted in the need for lab testing. His stool specimen and its subsequent disposal was my problem. My handbook said bum it. So burn it T did, in a five-gallon can with gasoline. Flames shot up almost six feet, and my next mistake was to extinguish them with carbon tetrachloride. This resulted in the production of lethal phosgene gas. The hospital had a near disaster. I could say that at that moment I vowed to write a how-to book so that such stupidities could be avoided. Nevertheless, when I was offered the opportunity to edit this book I thought back on the need for a real, practical treatment of my subject. This book, then, is a practical handbook for technical service personnel and scientists who are not necessarily specialists in microbiology. It provides information on suitable antimicrobial agents appropriate to their particular problem-solving needs and information on the microbial groups contributing to the specific problem, their ecologies, and strategies for controlling their access to the area or material of interest.