Bidi smoke, a complex mixture of toxic and carcinogens chemicals causes a large and growing number of premature deaths in South Asian countries especially in India and Bangladesh. The evolved products during the thermal degradation of bidi tobacco powder (BTP) have been measured by using TG-FrIR-MS technique. The results revealed that the main gases and volatile products released during the combustion and pyrolysis of BTP are CO, CO2, NH3, HCN, NO, isoprene, formaldehyde, acetaldehyde, acrolein, etc. Still others such as nicotine, phenol, polyaromatic hydrocarbon and some tobacco specific nitrosamines are contained in submicron sized solid particles that are suspended in Bidi smoke. The intensity or the quantity of evolved products is higher during the combustion than pyrolysis of BTP. The evolved chemical data suggest that Bidi smoke is responsible for cancer of the throat, oral cavity, pharynx, larynx, lungs, esophagus, stomach, and liver. (C) 2011 Elsevier B.V. All rights reserved.