This article attempts to examine the history of the American Red Cross mission in Russia aimed at providing medical care to sick and wounded Russian soldiers during World War I. Currently, in Russian and foreign historiography, humanitarian cooperation between Russia and the United States is presented in a fragmented and unsystematic manner, and this topic has not received the deserved academic attention. The author has identified the following objectives of this research: to analyze and supplement the existing material on the activities of the American Red Cross mission in Russia, to identify the features and mechanisms of its work, and to draw a general conclusion about the significance of this mission for the United States and Russian-American relations in particular. The article is based on materials from American periodical press and archival sources from the Russian State Historical Archive, Russian State Military Historical Archive, and Russian State Archive of the Navy. The research concludes that under the conditions of an unprecedented war, this assistance could not play a significant role in establishing Russian sanitary corps. However, this objective is not the only measure of the mission’s importance. In fact, the American Red Cross mission became one element of the indirect participation of the United States in the war before April 1917, as well as a tool for promoting the American Red Cross among the American population. In Russian-American relations, the mission was part of public diplomacy and international communication aimed at strengthening trust and mutual goodwill between both peoples.