The article documents and differentiates two kinds of translation officials in the central government of the Tang dynasty (618–906 AD) in medieval China: translators in the Court of Diplomatic Reception (Yiyu 譯語) and translators in the Secretariat (Fanshu Yiyu 蕃書譯語). The distinction between them is essential because they are often mentioned in the scholarly literature indiscriminately. Given the scarcity of historical records and the absence of focused discussions about translators in Tang times, their differences were usually either toned down as minimal or misinterpreted by modern scholarship over the past decade. Although some researchers have recently made reference to the two translator titles and agreed that their translation and interpreting duties were somewhat different, the nature of these differences has not been clearly established. Analysis of standard historical records suggests that, in fact, these two types of translators had distinct job duties. Translators in the Court of Diplomatic Reception interpreted primarily for foreign envoys, while the Secretariat’s translators chiefly translated state letters from foreign envoys. This article presents evidence to substantiate this observation and explain why such an apparently straightforward categorization has not been put forward thus far.