The integrated absorbance areas of vibrational bands of CO[subscript 2], CO, and CH[subscript 4] gases in cigarette smoke were measured from Fourier transform infrared (FTIR) spectra to derive the partial pressures of these gases at different smoke times. The quantity of the three gas-phase components of cigarette smoke at different smoke times were then determined. The concepts and applications of the FTIR spectroscopic technique, the Beer-Lambert law, infrared band strengths, emission rates of gases, ideal gas law, and experimental hazards were effectively demonstrated and discussed for a laboratory experiment intended for upper-division undergraduate chemistry students. (Contains 1 table and 5 figures.)