Although the environmental influence of Greek affiliation on drinking has been established, little is known about intrapersonal characteristics that make individuals susceptible to this influence. Self-consciousness (attending to one's self) was hypothesized to represent dispositional vulnerability to environmental influence. The potential moderating effect of self-consciousness on the relation between Greek involvement and drinking was examined longitudinally among college students (N = 319). The effect of Greek status was moderated by private and public self-consciousness and by gender. Specifically, non-Greek members' drinking was not influenced by self-consciousness. However, sorority members increased drinking as private self-consciousness increased, whereas fraternity members increased drinking as private and public self-consciousness decreased. These findings indicate that the "Greek effect" interacts with individual characteristics to affect drinking.