In view of the paucity of primary sources in English on Lithuanian interwar history, the unpublished private diaries of the United States consul in Lithuania from 1926 to 1928 a critical period in the history of the Lithuanian state which included the coup d'etat of December, 1926 have a special interest.' They provide a daily record by a careful foreign observer of Lithuanian life, political events, and, of course, the life of the small diplomatic community in Kaunas. The United States consul in Lithuania from 1926 to 1928 was Robert Wayne Heingartner (1881-1945), a career foreign service officer. He was born of German-American ancestry in Canton, Ohio, and after being educated in Ohio's public schools and by tutors in Europe (his father had also been a U. S. consul, whose career included a term as consul in Riga), he became a consular agent at Carini, Italy, in 1904. Posts in Trieste (as deputy consul, 1904-1906) and Vienna (1907-1917) followed. In Vienna, Heingartner became vice consul (1915-1917), and was attached to the Spanish Embassy when the United States entered the war against the Central Powers. After postwar assignment to the American Legation in Berne, he returned to Vienna, where he married Lily Kraus (d. 1934), daughter of a well-to-do assimilated Viennese Jewish family. After his stint as U. S. consul in Kaunas, Heingartner was transferred to Frankfurt am Main, where he witnessed the rise of Hitler and the establishment of the Nazi regime (1928-1939). After three years in Regina, Saskatchewan (1939-1942), Heingartner retired, returning to Ohio, where he died on February 18, 1945. 2 Throughout his period in Kaunas,3 Heingartner kept a private diary, which he wrote up on a daily basis, typing a neat copy every few months in leisure periods.4 While the diaries reflect a somewhat reserved and reticent personality, they also show a meticulous observer, who kept a detailed and unfailingly regular account of anything of interest. The areas on which the diaries cast some light are: social conditions in interwar Lithuania (mainly Kaunas), as perceived by a Western observer; political developments; and the life of the diplomatic community. Not only are Heingartner' s observations of some intrinsic interest, they also add to our picture of how Lithuanian affairs in the 1920s were perceived by the outside world, especially the United States.