In the elections held on 13 June 1999, the right to vote was exercised by only 66.25% of the 461,729 people registered on the electoral rolls, which meant that abstention amounted to 33.75%. The results were as follows: UPN 22 seats (125,497 votes), PSN-PSOE 11 seats (61,531 votes), EH 8 seats (47,271), IU-EB 3 seats (20,879); CDN 3 seats (20,821; and EA/EAJ-PNV 3 seats (16,512 votes).
Following these results, the third regionalist government took office presided over by the candidate from UPN, Miguel Sanz Sesma. The composition of this government was as follows