It comprises 36 legislators, elected in each of the 18 departments of La Rioja.

[1] The legislature was established by the first provincial constitution, adopted in 1855, and convened for the first time on 18 March 1856.

[2] Out of the 18 departments, 12 elect a single legislator, and thus employ the first-past-the-post system.

The remaining six departments employ proportional representation to elect its multiple legislators.

The current vice governor, elected in 2019, is Florencia López, of the Justicialist Party.