Carbon monoxide (CO) is a colourless, odourless, highly toxic, poisonous gas. Exposure to a few hundreds ppm can cause permanent health damages or death. CO can thus be considered as one of the most dangerous environmental pollutants and therefore, its removal and detection is of extreme importance for safe living. This book presents current research in the study of the sources, uses and hazards of carbon monoxide. Topics discussed include the cardiac effects of carbon monoxide intoxication; CO oxidation using gold supported on Ce-Mn-O composite materials; heterogeneous catalysis in carbonylative coupling reactions; and, the evaluation of carboxyhemoglobin (CO-Hb) by oximeter in the forensic practice.