In a speech attributed by Xenophon to Jason of Pherae, Thessaly is described as an exporter of grain, in contrast with Athens which was obliged to supplement its own foodstocks with the surplus of others. The ancient sources record the dispatch of Thessalian grain to a few Greek cities; but Thessaly must have been a resource for other Greeks in peacetime, as it was in wartime to Roman armies operating in the region in the middle and late Republic. A newly published inscription from Larisa indicates that on one occasion in the middle of the second century B.C. the Thessalians actually provided grain for the Roman populace itself, in response to a request delivered to the Thessalian koinon by a Roman magistrate. Our main objective in this paper is to place this inscription in a suitable historical context and explain its significance for Rome and Thessaly.