The mosque unites Mughal architecture and Italian styles. The plans were done by Booty and Edwards Chartered Architects according to designs by the Italian architect Cavaliere Rudolfo Nolli, who had already for decades been working at the gulf of Siam.
The mosque's most recognizable feature, the main dome, is covered in pure gold. The mosque stands 52 m (171 ft) high and can be seen from virtually anywhere in Bandar Seri Begawan. The main minaret is the mosque's tallest feature. In a unique way it mixes Renaissance and Italian architectural style. The minaret has an elevator to the top, where one can enjoy a panoramic view of the city.
The interior of the mosque is for prayer only. It has magnificent stained glass windows, arches, semi-domes and marble columns. Nearly all the material used for the building has been imported from abroad: the marble from Italy, the granite from Shanghai, the crystal chandeliers from England and the carpets from Saudi Arabia.