Abstract: Ruch et al. (1993. Toward an empirical verification of the general theory of verbal humor. Humor 6 (2). 123–36.) found that ordinary college students perceived joke similarity in a pattern that largely but not completely matched the pattern predicted by the General Theory of Verbal Humor (GTVH, Attardo and Raskin. 1991. Script theory revis (it) ed: joke similarity and joke representation model. Humor 4 (3–4). 293–47.). Stand-up comedians must not only perform jokes in front of audiences, but must write the jokes they deliver. Joke theft, the telling of a joke written and performed by another comedian without express permission, is a serious violation of community norms. A stolen joke need not have the same precise wording, hence it may be hypothesized that stand-up comedians would develop an increased sensitivity to joke synonymy. In the present study, working comedians rated joke similarity using a similar procedure to that of Ruch et al. (1993. Toward an empirical verification of the general theory of verbal humor. Humor 6 (2). 123–36.). While the comedians’ responses did not differ dramatically from those of non-comedians in Ruch et al. (1993. Toward an empirical verification of the general theory of verbal humor. Humor 6 (2). 123–36.), their perceived similarity followed the pattern predicted in the GTVH more closely. These findings suggest slightly but not markedly greater sensitivity to joke synonymy among working comedians and offer further empirical support for the GTVH.