A microcomputer aided, battery operated method for analysing puff parameters during smoking was developed. The equipment included a sensitive, differential pressure transducer, a portable microcomputer and a modified cigarette flowmeter. The method is based on measuring pressure differences between two points within the flowmeter. The pressure difference is linearly proportional to smoke flow according to the Poiseuille-Hagen principle. The calibration curve, the mean flow as a function of (the area of puff curve)/puff duration, showed to be linear (r = 0.99) for calculating flow and volume of smoke. In experiments with 11 male volunteers the total inhalation volume reached the range 296-678 ml, the mean puff volume 19-65 ml, the mean puffing rate 15-26 ml/s, the mean puff duration 1.3-3.5 s, the number of puffs 9-16 and the mean interval between puffs 17-25 s.