As a state museum, it houses a large collection of Kedah's historical, culture, and royal heritages. The collection includes early Chinese porcelain, artefacts from the archaeological excavations in Lembah Bujang (Bujang Valley) and a fabulous pokok bunga emas or 'gold tree' produced as a tribute to the Thais.

The museum is also a research centre on Kedah's civilisation. Before the present premise was built in 1936, the museum - officially opened by the then Kedah Mentri Besar Tan Sri Tunku Ismail Tunku Yahya (Tunku indera Setia), on February 3, 1957 - was located in the Balai Besar (Grand Hall).