Being able, outspoken and hard working, Šmeral was elected to the executive committee of social democracy (in 1909) and into the parliament of Austria (Reichsrat), in 1911.

He advocated federalization of Austria-Hungary as the best way to achieve the goals of the worker's movement and argued against creation of small national states.

After 28 October 1918, when Czechoslovakia was established, he refused to participate in politics of the new state and until the end of 1919 worked as a correspondent of Právo lidu in Switzerland.

After his return, he led the left-wing of Social Democracy, preparing for the creation of the communist party and participated in work of the Comintern.

In September 1938, after the Sudetenland Crisis resulted in the Munich Agreement, he left for Moscow and joined the exiled leadership (zahraniční vedení) of the KSČ (soon banned in Nazi-occupied Czechoslovakia).