Unfortunately, only a small percent of pathological gamblers seek the professional help they need. In the current study, we test the idea that individual differences in reward sensitivity should predict whether a pathological gambler has sought treatment—the odds of treatment seeking should decrease as reward sensitivity increases. This hypothesis rests on the proposition that reward sensitive pathological gamblers should find treatment seeking aversive because doing so would remove a route to reward. We also tested those motivations to gamble that are positively reinforcing (social affliction and self-enhancement) as a possible mechanism by which reward sensitivity undermines treatment seeking—we did not anticipate negatively reinforcing motivations (e.g., coping) to be a mechanistic variable. Ninety-two pathological gamblers completed a large-scale survey that contained the variables of interest. As predicted, pathological gamblers were less likely to have sought treatment as reward sensitivity increased. Moreover, this relationship was mediated by social affiliation motivations to gamble, but not self-enhancement or coping motives. Reward sensitive gamblers did not wish to seek treatment to the extent that they were motivated to gamble for the social interactions it provides—seeking treatment would cut this avenue of affiliation with others. In light of these results, we suggest health care professionals take reward sensitivity into account when trying to promote treatment seeking, to say nothing of the social affiliation motives that underlie the reward sensitivity-treatment seeking link.