fMRI studies have found that brain areas associated with the reward of relationship self-expansion are also the same areas that are associated with the reward of smoking cigarettes (Aron et al., 2005; Ikemoto et al., 2006; Xu et al., 2011). This raises the possibility that one reward may be able to substitute for another, and that self-expansion may be able to aid in smoking abstinence and cessation. One recent study found that successful quitters experienced significantly more self-expanding experiences (both in and out of the relationships context) immediately prior to their quitting, and even unsuccessful quitters were able to abstain longer as a function of how many self-expanding experiences they had prior to their quit attempt (Xu, Floyd, Westmaas, & Aron, 2010). The current studies build upon the idea of replacement by experimentally manipulating self-expansion and using fMRI to investigate whether craving attenuation is the mechanism behind this effect. In Study 1, smokers who were in a new romantic relationship abstained from smoking overnight and then viewed pairs of photographs in the scanner. Each pair consisted of one headshot and one object image. Headshots were either self-expanding (an image of their romantic partner) or not self-expanding (images of a friend or neutral acquaintance). Object images were either a pencil (control) or a cigarette (craving cue). When smokers viewed cigarette images alongside a photo of their partner, they exhibited less activation of areas in the brain associated with craving than when the cigarette image was alongside the non self-expanding photos. In Study 2, smokers in long-term relationships (at least 2 years) abstained from smoking overnight and then, while in the scanner, played a series of cooperative two-player games with their partner. Games were randomized to be either self-expanding (novel, exciting, and challenging) or merely pleasant but not self-expanding, and some versions of the games contained smoking cues. Smokers showed less craving area activations when viewing smoking cues during self-expanding games as opposed to non self-expanding games. These studies provide evidence that self-expansion rewards can undermine craving for cigarettes in smokers. Implications for interventions and future studies are discussed.