Born in Bochnia in the Galicia area of Austria-Hungary, Rimalt studied at a heder and yeshiva, as well as a Hebrew high school in Kraków.

In 1939 he emigrated to Mandatory Palestine and worked as headmaster of a school in Ramat Gan.

In 1951 he was elected to the Knesset on the General Zionists list, and was also a member of Ramat Gan city council, serving as deputy mayor responsible for education between 1955 and 1959.

By that time the General Zionists had merged into the Liberal Party, which had become a faction within the Gahal alliance (later Likud); Rimalt was appointed chairman of the Liberal Party's directorate in 1965, having won re-election to the Knesset in 1955, 1959, 1961 and 1965.

Following the formation of a national unity government after the 1969 elections, Rimalt was appointed Minister of Postal Services.