We refine our Boundary Model of the regulation of drug intake and apply it to several examples from cigarette smoking. Our model demands the simultaneous consideration of biological and psychosocial controls. The biological factors include the physiological demand to maintain minimum levels of nicotine, direct rewarding effects of tobacco, and toxic effects of excessive smoking. The psychosocial factors include “voluntary”, self-initiated controls as well as situational influences. In light of the model, we review and consider the problems with techniques commonly used to control smoking, and we discuss the inferential confusions faced by smokers and researchers.