This study examines how smoking history, cigarette yield and smoking behavior relate to smoke exposure as determined by smoke constituents and their metabolic products in peripheral blood. Recruited without regard to the nicotine yield of their cigarette, male smokers smoked their own cigarettes ad libitum, including one cigarette five minutes prior to venipuncture. Smokers had significant (p = 0.0001) elevations of serum thiocyanate, blood carboxyhemoglobin, plasma nicotine, and cotinine concentrations each of which was significantly associated with past 24-hour cigarette consumption. The nicotine yield of the cigarette significantly correlated with plasma cotinine concentrations and with the smoking behavior variables. Most notably, smokers consuming lower nicotine yielding cigarettes exhibited an increased total puff volume per cigarette, suggesting that smokers of low nicotine yielding cigarettes compensate for these low yields by their smoking behavior. However, the fact that lower plasma cotinine concentrations are present in smokers of low-nicotine cigarettes suggests that this compensation is incomplete. That smoking behavior variables relate to smoke exposure was demonstrated by a significant linear correlation between plasma nicotine and mean puff interval in the total smoking population and between plasma nicotine and total puff volume per cigarette in a subpopulation smoking a single brand of cigarette. These data suggest that smoking history, nicotine yield of the cigarette and smoking behavior are all determinants of smoke exposure. Further, although smokers of low-yield cigarettes appear to compensate by puffing larger volumes per cigarette, this compensation appears to be inadequate to attain an equivalent smoke exposure.(ABSTRACT TRUNCATED AT 250 WORDS)