Interrelationships between puffing, puff duration, puff volume, and heart rate change were assessed in a sample of 63 chronic, high rate smokers. Results showed puff duration and volume were related for males and females, and that heart rate change was related to volume in males and puff duration in females. Puffs were not related to either volume or heart rate change in males or females. These results call into question research on smoking behavior which does not measure volume, and shows that components of puffing may not be used interchangeably, and that neither puffs nor puff duration are accurate predictors of volume of intake.