Since 1988, when he was a high-school student, he has taken part in organizing student protests against the government in Myanmar. He became Vice-General Secretary of the unauthorized Basic Education Student Union (BESU) in 1989.

He was dismissed from school and imprisoned in September 1991 for nine months because of his BESU activities. During this period of detention he was reportedly severely tortured.

Following his release he became a leading member of the All Burma Federation of Student Unions, the unauthorized umbrella organization for student unions in Myanmar. He again became involved in publishing leaflets and organizing demonstrations, and was forced to go into hiding after the authorities tried to arrest him in 1994. He nevertheless took part in student demonstrations in December 1996 and, in 1998, helped to organize student protests against the poor quality of education and denial of human rights.

Thet Win Aung was finally arrested in October 1998. In January 1999 he was sentenced to 52 years’ imprisonment, which was increased to 59 years after further interrogation.

He was reported to have been tortured immediately following his arrest, and there were concerns for his health. He died on 16.10.06 in Mandalay Jail under mysterious circumstances.