He earned a medical degree at the University of Córdoba, and later founded the Colegio Médico de la Provincia.

[1] On 16 May 1999, Avelín was elected as governor of his province with 55%, heading the list of the Alliance for Work, Justice and Education, which would win the presidency of Argentina later the same year.

Like the rest of the nation, San Juan experienced economic upheaval and unrest during his term in office; by 2001, wages were not being paid to provincial employees, and the province was bankrupt.

[2] Following the downfall of the government of President de la Rua, Avelín was a fierce opponent of the austerity measures proposed by the International Monetary Fund, saying, "The only thing lacking for us is to pull down the Argentine flag and replace it with the IMF's."

[4] His daughter, Nancy Avelín, who also served as a senator, was eventually the candidate for the Renewal Crusade that year.