This article brings together the trade records of the Dutch and English East India Companies' merchants, chronicles in Arabic, and a published French travel narrative to shed light on an overlooked phenomenon, that of early modern medical diplomacy to Qasimi Yemen during the early eighteenth century. In this era foreign merchants flocked to the southern Arabian Peninsula, many with the interest of procuring coffee, a commodity that was then still difficult to purchase elsewhere. Along with them came doctors and ships' surgeons, who were called on to treat Yemen's imam al-Mahdi Muhammad (d. 1718), who suffered from many ailments in the last years of his rule. This study illustrates that these episodes of early modern cross-cultural health care were not peripheral or secondary to the large-scale political interests of overseas envoys or the immediate commercial involvements of foreign merchants but rather tightly intertwined with them. In addition to documenting heretofore unremarked upon events, the larger objective of this study is to investigate the role foreigners played as both agents of exchange and recorders of events in Yemen's early modern history.