The Malta Blue Books date back to the times of the British Administration of the 19th and 20th Centuries. The British Empire set high standards for the collection and availability of information with regard to several aspects of life in its colonies. Indeed, it can be said that the single most significant resource of information in British colonies and dominions was the Blue Book. The NSO has an impressive collection which is only rivalled by the one at the Mdina National Archives.

The volumes comprise a wealth of statistics: population; vital statistics; imports and exports; taxes, duties and other revenue sources; infrastructural projects; civil and military expenditure; education; hospitals; the penal system; and climate statistics. Some Blue Books contain very distinctive illustrative material. This may range from beautiful watercolours of local flora, to delicately drawn section maps and street plans.

The digitisation project undertaken by the NSO was originally facilitated by an EU grant. By the time the grant was terminated, a proportion of the volumes had been digitised and placed online. Now the full complement of 116 volumes can be consulted online, therefore providing service while at the same time saving wear and tear to the original artefacts.

The project was made possible by ongoing co-operation with the National Archives of Malta.