At the age of 11, he was sent away from home to study Torah, and studied at the Yeshivas in Skaudvilė and Kuršėnai, until the First World War erupted in 1914 and turned the world around. During the war years, Ish-Shalom studied under the town's rabbi, but whereas at the Yeshiva he had dedicated most of his time to Torah studies and little time to an autodidactic acquisition of a general education, now that proportion was reversed, to the point that people in the town began calling him "Baruch Spinoza". During those years, he also began to experience public activity, having led a group of youths which helped Jews who had escaped from German forced labor camps.
In 1923 he immigrated to Eretz Israel. Once there, he joined the members of the Labor Battalion at Tel Yosef, where he worked mainly in the draining of swamps, until he moved to the Labor Battalion's company in Jerusalem, where, in the early 1920s, he headed a group of builders.
In 1950 he was appointed as a member of the Jerusalem City Council on behalf of Mapai.
In 1955, he was appointed as Deputy to Gershon Agron, Mayor of Jerusalem.
In December of 1959, following the elections to the City Council, he was elected as Mayor of Jerusalem, having served as acting mayor for a month following Agron's death (who had died several days before the elections).
In the elections to the Jerusalem Municipality in 1965, he was defeated by Teddy Kollek, who headed the Rafi list and was appointed as mayor. In 1967, during the Six-Day War, Ish-Shalom, at the head of his party, joined the coalition, and became Kollek's deputy.
Having been dislodged from the second place in the consolidated list of Rafi and Mapai in 1969, he withdrew his candidacy, and did not run for office in the City Council again.
He died on the 7th of Adar, 5751, and was buried at Har HaMenuchot. Ish-Shalom refused to have a street named after him. HaSatat Street in Beit HaKerem neighborhood commemorates his early years in Jerusalem in the 1920s.