Due to the occupation of the Vilna region by the Polish army in 1920, Aran became a border town and the river Merkys became the border between Poland and Lithuania. The Jewish community of Aran was also divided and 15 families remained on the Polish side of the town, but they managed to return to the Lithuanian side of the town later, and rebuilt their lives anew.

During this period Aran was a county center as before, in the Alytus district.

According to the autonomy law for minorities, issued by the new Lithuanian government, the Minister for Jewish affairs Dr. Max (Menakhem) Soloveitshik ordered elections to be held in the summer of 1919 for community committees in all towns of the state. In Aran a committee was elected, which collected taxes as required by law and which was in charge of most aspects of community life, acting till the end of 1925 when the autonomy was annulled.

According to the first census carried out by the government in 1923, Aran had 399 Jews (180 men and 219 women). But the number of Jews diminished, many emigrated to America, Argentina, Uruguay and some of the youth to Eretz-Yisrael. One of them, Shelomoh Kaplan (1920-1948) was killed by a shell in Jerusalem in May 1948 when rushing to help a wounded woman.

During the first years of independent Lithuania (1919-1920), Aran's Jews suffered from adverse economic conditions and received help from "YeKoPo" (Committee for helping Jewish refugees) who provided remarkable sums of money for food, timber for heating, medical care, loans for artisans and for baking Matsoth for Pesakh.

During this period Aran's Jews made their living from commerce, crafts, agriculture, and in particular from the military camps in the vicinity as well as the weekly market day every Tuesday. Many Jewish labourers worked in the cardboard factory of David Yershansky. The timber trade which had developed before the war, suffered because Vilna and its region were now on the other side of the border.

The beautiful view and fresh air in Aran and its surroundings attracted many vacationers in the summer months, and this too added to the income of the town's Jews.

In 1937 28 Jewish artisans worked in the town: 5 tailors, 5 butchers, 4 shoemakers, 3 bakers, 3 stitchers, 2 blacksmiths, 1 hatter, 1 carpenter, 1 knitter, 1 barber, 1 photographer, 1 tinsmith. Meir Levin was the doctor and pharmacist.

The Folksbank, directed by Iser Veksler and with 99 members in 1927, played an important role in the economic life of Aran's Jews. But despite this the economic situation in town grew worse and many families left, in particular the youth, in order to search for a living elsewhere, with many moving to Kovno and others emigrating abroad.

Among the 13 telephone subscribers in 1939 there were no Jews.

Jewish children studied at the Hebrew school of the "Tarbuth" chain, with a complement of about 60 children in the twenties, decreasing to only 30 by1930. In the same year 25 boys studied at the local Talmud-Torah.

Immediately after the war a library had been established, comprising about 1,500 books in 1937, half of them in Hebrew, which contributed much to the education of the youth. During these years literary and musical evenings were held, their income being donated to the library and to the "Literaten Farein" (Society of Literature), which was founded in 1937. In April of that year a party was arranged on the initiative of Ozer Ingel, who also delivered a lecture on " Yiddish literature in accordance with the jubilee of the writer Opatoshu", speaking Lithuanian because half the audience were Lithuanians. The artistic part of the evening was performed by Meir Levdon and Pesakh Tatarsky.

Many of Aran's Jews were members of the Zionist movement and in the elections for Zionist congresses they voted for most of the Zionist parties, as can be seen from the results enumerated in the table below:

Fund raising for "Keren HaYesod", "Keren Kayemeth" and Kapa"i (Fund of Eretz-Yisrael workers) took place. The Zionist youth organizations active in Aran were "Gordonia", "Hashomer-Hatsair" and "Betar".

The Synagogue and the Beth-Midrash were the home for learning, for the "Shas" (Mishnah and Talmud) society as well as the "Tifereth Bakhurim" group for the youth.

Among the welfare societies there were "Gemiluth Khesed" and "Hakhnasath Kalah" (Support for poor brides) and the "Khevrah Kadisha". In 1879 the "Gabaim" (Chairmen) of the "Shas" society were Yisrael Kaplansky (?) and Meir Kalvarisky, of the "Khevrah Kadisha - Yosef Shlevin and Tsevi-Dov Levitan.

Among the personalities born in Aran were:

Shalom Cohen (1889-1955), who wrote many works of research on the history of Jewish doctors in the world, mostly written in English, some in Hebrew. He died in New York.

Avraham Blekharovitz, a known cantor, who at the age of 21 was the first soloist at the Riga State Theater. He was chief cantor in Buenos Aires in the fifties, and later on a concert-singer in New-York.