Air pollution through fine and ultra-fine particles is a major threat to human health in cities of developed and especially of developing countries. Carbon Monoxide (CO) is the main pollutant in industries, residence and rural areas, CO is commonly referred as the “silent Killer”. CO is extremely toxic and often effects victims in such a manner that they fail to recognize the liability. In certain countries, even higher levels of fine particles occur in the indoor environment due to open stove cooking and heating. The carbon monoxide is mainly released in traffic areas, and Parking garages. There are many sources that are Vehicles’ carbon monoxide sources, Home carbon monoxide sources, Travel carbon monoxide sources, Work carbon monoxide sources etc.,and there are so many effects caused by carbon monoxide. In this present work the detailed description on different types of sensing technologies like Solid state Sensors, Electro Chemical Sensors are used for finding CO and remedial measures to control CO are reviewed.