He started working as a teacher in 1971, aged 21. He joined the teachers' union, and voted for the creation of the CTERA union in 1973. He was fired in 1978, during the National Reorganization Process. He started to work again in 1981, in Lomas de Zamora, recreating the local teachers' union. He was elected secretary general of SUTEBA in 1994.[1]
He was elected secretary general of the CTA in 1997. Back then, he opposed the policies of president Carlos Menem, and took part in a hunger strike at the Carpa blanca.[1] There were new elections in 2011, and he was initially defeated by Pablo Micheli, who opposed the president Cristina Fernández de Kirchner, supported by Yasky. The elections were contested, and the judiciary confirmed Yasky as president. Micheli considered that the presidency would have interfered in the elections via loyalist judges, and Yasky that the judiciary confirmed their suspicions about electoral fraud.[2]
