Puffing topography variables were measured in a well-characterized, male population smoking their own brand of cigarette. Of the puffing topography variables, interpuff interval appeared to be the primary determinant of blood concentrations of smoke constituents: however, preliminary data in a homogeneous population according to the nicotine yield of their cigarette suggest that total puff volume per cigarette may also be a significant determinant of blood levels of smoke constituents. Smokers of low nicotine yield cigarettes partially compensated for these lower yields by increasing the total volume puffed per cigarette. Observed differences in puffing topography associated with increased daily cigarette consumption and cumulative smoking history were consistent with a higher smoke exposure per cigarette. Further, although both alcohol and coffee consumption are associated with present and cumulative smoking history, coffee consumption is uniquely associated with differences in puffing topography consistent with a higher smoke exposure per cigarette. However, by multiple regression analyses, neither coffee nor alcohol consumption histories added significantly to the prediction of blood concentrations of smoke constituents over that obtained by smoking history and puffing topography.