[1] Voting for the Parliament was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered in La Rioja and in full enjoyment of their political rights.

[2] The expat vote system was attributed responsibility for a major decrease in the turnout of Spaniards abroad during the years it had been in force.

[3] The 33 members of the Parliament of La Rioja were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of five percent of valid votes—which included blank ballots—being applied regionally.

[1][4][5] The president had the prerogative to dissolve the Parliament of La Rioja and call a snap election, provided that no motion of no confidence was in process, no nationwide election was due and some time requirements were met: namely, that dissolution did not occur either during the first legislative session or within the legislature's last year ahead of its scheduled expiry, nor before one year had elapsed since a previous dissolution.

The highest percentage figure in each polling survey is displayed with its background shaded in the leading party's colour.