Their acts became known only early this month after their mother, Jian Jing-tze, passed away at the age of 68.
Tsai Jing-yin, wife of Hsinchu Mayor Hsu Ming-tsai, said Jian was an active member of the women's association in the city.
According to Tsai, Jian single-handedly raised a son and daughter after her husband's death. But her health was compromised by hard work. She developed kidney problems 20 years ago.
Jian had persistently refused a proposal from her son and daughter, who competed with each other to donate a kidney to her.
The elder brother eventually had one of his kidneys transplanted for his mother.