The daughter of United Malays National Organisation (UMNO) activists, Napsiah was born in Negeri Sembilan.
From 1969 to 1982, Napsiah taught at the Universiti Pertanian Malaysia, becoming associate professor and head of the Department of Human Studies.
She was elected to the Dewan Rakyat representing the constituency of Kuala Pilah (1982-1995; 1999–2004) and was named Deputy Minister of Housing and Local Government.
She became divisional head of Wanita UMNO (the women's wing) and was also named to its national executive council.
[1] In 1999 general election, she contested again the Kuala Pilah parliamentary seat and won for another one term.